/**
 * pugixml parser - version 1.10
 * --------------------------------------------------------
 * Copyright (C) 2006-2019, by Arseny Kapoulkine (arseny.kapoulkine@gmail.com)
 * Report bugs and download new versions at https://pugixml.org/
 *
 * This library is distributed under the MIT License. See notice at the end
 * of this file.
 *
 * This work is based on the pugxml parser, which is:
 * Copyright (C) 2003, by Kristen Wegner (kristen@tima.net)
 */

#ifndef SOURCE_PUGIXML_CPP
#    define SOURCE_PUGIXML_CPP

#    include "pugixml.hpp"

#    include <assert.h>
#    include <limits.h>
#    include <stdio.h>
#    include <stdlib.h>
#    include <string.h>

#    ifdef PUGIXML_WCHAR_MODE
#        include <wchar.h>
#    endif

#    ifndef PUGIXML_NO_XPATH
#        include <float.h>
#        include <math.h>
#    endif

#    ifndef PUGIXML_NO_STL
#        include <istream>
#        include <ostream>
#        include <string>
#    endif

// For placement new
#    include <new>

#    ifdef _MSC_VER
#        pragma warning(push)
#        pragma warning(disable : 4127)    // conditional expression is constant
#        pragma warning(disable : 4324)    // structure was padded due to __declspec(align())
#        pragma warning(disable : 4702)    // unreachable code
#        pragma warning(disable : 4996)    // this function or variable may be unsafe
#    endif

#    if defined(_MSC_VER) && defined(__c2__)
#        pragma clang diagnostic push
#        pragma clang diagnostic ignored "-Wdeprecated"    // this function or variable may be unsafe
#    endif

#    ifdef __INTEL_COMPILER
#        pragma warning(disable : 177)          // function was declared but never referenced
#        pragma warning(disable : 279)          // controlling expression is constant
#        pragma warning(disable : 1478 1786)    // function was declared "deprecated"
#        pragma warning(disable : 1684)         // conversion from pointer to same-sized integral type
#    endif

#    if defined(__BORLANDC__) && defined(PUGIXML_HEADER_ONLY)
#        pragma warn - \
            8080    // symbol is declared but never used; disabling this inside push/pop bracket does not make the warning go away
#    endif

#    ifdef __BORLANDC__
#        pragma option push
#        pragma warn - 8008    // condition is always false
#        pragma warn - 8066    // unreachable code
#    endif

#    ifdef __SNC__
// Using diag_push/diag_pop does not disable the warnings inside templates due to a compiler bug
#        pragma diag_suppress = 178    // function was declared but never referenced
#        pragma diag_suppress = 237    // controlling expression is constant
#    endif

#    ifdef __TI_COMPILER_VERSION__
#        pragma diag_suppress 179    // function was declared but never referenced
#    endif

// Inlining controls
#    if defined(_MSC_VER) && _MSC_VER >= 1300
#        define PUGI__NO_INLINE __declspec(noinline)
#    elif defined(__GNUC__)
#        define PUGI__NO_INLINE __attribute__((noinline))
#    else
#        define PUGI__NO_INLINE
#    endif

// Branch weight controls
#    if defined(__GNUC__) && !defined(__c2__)
#        define PUGI__UNLIKELY(cond) __builtin_expect(cond, 0)
#    else
#        define PUGI__UNLIKELY(cond) (cond)
#    endif

// Simple static assertion
#    define PUGI__STATIC_ASSERT(cond)                                    \
        {                                                                \
            static const char condition_failed[(cond) ? 1 : -1] = { 0 }; \
            (void)condition_failed[0];                                   \
        }

// Digital Mars C++ bug workaround for passing char loaded from memory via stack
#    ifdef __DMC__
#        define PUGI__DMC_VOLATILE volatile
#    else
#        define PUGI__DMC_VOLATILE
#    endif

// Integer sanitizer workaround; we only apply this for clang since gcc8 has no_sanitize but not unsigned-integer-overflow and produces
// "attribute directive ignored" warnings
#    if defined(__clang__) && defined(__has_attribute)
#        if __has_attribute(no_sanitize)
#            define PUGI__UNSIGNED_OVERFLOW __attribute__((no_sanitize("unsigned-integer-overflow")))
#        else
#            define PUGI__UNSIGNED_OVERFLOW
#        endif
#    else
#        define PUGI__UNSIGNED_OVERFLOW
#    endif

// Borland C++ bug workaround for not defining ::memcpy depending on header include order (can't always use std::memcpy because some
// compilers don't have it at all)
#    if defined(__BORLANDC__) && !defined(__MEM_H_USING_LIST)
using std::memcpy;
using std::memmove;
using std::memset;
#    endif

// Some MinGW/GCC versions have headers that erroneously omit LLONG_MIN/LLONG_MAX/ULLONG_MAX definitions from limits.h in some
// configurations
#    if defined(PUGIXML_HAS_LONG_LONG) && defined(__GNUC__) && !defined(LLONG_MAX) && !defined(LLONG_MIN) && !defined(ULLONG_MAX)
#        define LLONG_MIN (-LLONG_MAX - 1LL)
#        define LLONG_MAX __LONG_LONG_MAX__
#        define ULLONG_MAX (LLONG_MAX * 2ULL + 1ULL)
#    endif

// In some environments MSVC is a compiler but the CRT lacks certain MSVC-specific features
#    if defined(_MSC_VER) && !defined(__S3E__)
#        define PUGI__MSVC_CRT_VERSION _MSC_VER
#    endif

// Not all platforms have snprintf; we define a wrapper that uses snprintf if possible. This only works with buffers with a known size.
#    if __cplusplus >= 201103
#        define PUGI__SNPRINTF(buf, ...) snprintf(buf, sizeof(buf), __VA_ARGS__)
#    elif defined(PUGI__MSVC_CRT_VERSION) && PUGI__MSVC_CRT_VERSION >= 1400
#        define PUGI__SNPRINTF(buf, ...) _snprintf_s(buf, _countof(buf), _TRUNCATE, __VA_ARGS__)
#    else
#        define PUGI__SNPRINTF sprintf
#    endif

// We put implementation details into an anonymous namespace in source mode, but have to keep it in non-anonymous namespace in header-only
// mode to prevent binary bloat.
#    ifdef PUGIXML_HEADER_ONLY
#        define PUGI__NS_BEGIN \
            namespace pugi     \
            {                  \
                namespace impl \
                {
#        define PUGI__NS_END \
            }                \
            }
#        define PUGI__FN inline
#        define PUGI__FN_NO_INLINE inline
#    else
#        if defined(_MSC_VER) && _MSC_VER < 1300    // MSVC6 seems to have an amusing bug with anonymous namespaces inside namespaces
#            define PUGI__NS_BEGIN \
                namespace pugi     \
                {                  \
                    namespace impl \
                    {
#            define PUGI__NS_END \
                }                \
                }
#        else
#            define PUGI__NS_BEGIN \
                namespace pugi     \
                {                  \
                    namespace impl \
                    {              \
                        namespace  \
                        {
#            define PUGI__NS_END \
                }                \
                }                \
                }
#        endif
#        define PUGI__FN
#        define PUGI__FN_NO_INLINE PUGI__NO_INLINE
#    endif

// uintptr_t
#    if (defined(_MSC_VER) && _MSC_VER < 1600) || (defined(__BORLANDC__) && __BORLANDC__ < 0x561)
namespace pugi
{
#        ifndef _UINTPTR_T_DEFINED
    typedef size_t uintptr_t;
#        endif

    typedef unsigned __int8  uint8_t;
    typedef unsigned __int16 uint16_t;
    typedef unsigned __int32 uint32_t;
}    // namespace pugi
#    else
#        include <stdint.h>
#    endif

// Memory allocation
PUGI__NS_BEGIN
PUGI__FN void* default_allocate(size_t size)
{
    return malloc(size);
}

PUGI__FN void default_deallocate(void* ptr)
{
    free(ptr);
}

template<typename T>
struct xml_memory_management_function_storage
{
    static allocation_function   allocate;
    static deallocation_function deallocate;
};

// Global allocation functions are stored in class statics so that in header mode linker deduplicates them
// Without a template<> we'll get multiple definitions of the same static
template<typename T>
allocation_function xml_memory_management_function_storage<T>::allocate = default_allocate;
template<typename T>
deallocation_function xml_memory_management_function_storage<T>::deallocate = default_deallocate;

typedef xml_memory_management_function_storage<int> xml_memory;
PUGI__NS_END

// String utilities
PUGI__NS_BEGIN
// Get string length
PUGI__FN size_t strlength(const char_t* s)
{
    assert(s);

#    ifdef PUGIXML_WCHAR_MODE
    return wcslen(s);
#    else
    return strlen(s);
#    endif
}

// Compare two strings
PUGI__FN bool strequal(const char_t* src, const char_t* dst)
{
    assert(src && dst);

#    ifdef PUGIXML_WCHAR_MODE
    return wcscmp(src, dst) == 0;
#    else
    return strcmp(src, dst) == 0;
#    endif
}

// Compare lhs with [rhs_begin, rhs_end)
PUGI__FN bool strequalrange(const char_t* lhs, const char_t* rhs, size_t count)
{
    for (size_t i = 0; i < count; ++i)
        if (lhs[i] != rhs[i]) return false;

    return lhs[count] == 0;
}

// Get length of wide string, even if CRT lacks wide character support
PUGI__FN size_t strlength_wide(const wchar_t* s)
{
    assert(s);

#    ifdef PUGIXML_WCHAR_MODE
    return wcslen(s);
#    else
    const wchar_t* end = s;
    while (*end) end++;
    return static_cast<size_t>(end - s);
#    endif
}
PUGI__NS_END

// auto_ptr-like object for exception recovery
PUGI__NS_BEGIN
template<typename T>
struct auto_deleter
{
    typedef void (*D)(T*);

    T* data;
    D  deleter;

    auto_deleter(T* data_, D deleter_) : data(data_), deleter(deleter_) {}

    ~auto_deleter()
    {
        if (data) deleter(data);
    }

    T* release()
    {
        T* result = data;
        data      = 0;
        return result;
    }
};
PUGI__NS_END

#    ifdef PUGIXML_COMPACT
PUGI__NS_BEGIN
class compact_hash_table
{
public:
    compact_hash_table() : _items(0), _capacity(0), _count(0) {}

    void clear()
    {
        if (_items) {
            xml_memory::deallocate(_items);
            _items    = 0;
            _capacity = 0;
            _count    = 0;
        }
    }

    void* find(const void* key)
    {
        if (_capacity == 0) return 0;

        item_t* item = get_item(key);
        assert(item);
        assert(item->key == key || (item->key == 0 && item->value == 0));

        return item->value;
    }

    void insert(const void* key, void* value)
    {
        assert(_capacity != 0 && _count < _capacity - _capacity / 4);

        item_t* item = get_item(key);
        assert(item);

        if (item->key == 0) {
            _count++;
            item->key = key;
        }

        item->value = value;
    }

    bool reserve(size_t extra = 16)
    {
        if (_count + extra >= _capacity - _capacity / 4) return rehash(_count + extra);

        return true;
    }

private:
    struct item_t
    {
        const void* key;
        void*       value;
    };

    item_t* _items;
    size_t  _capacity;

    size_t _count;

    bool rehash(size_t count);

    item_t* get_item(const void* key)
    {
        assert(key);
        assert(_capacity > 0);

        size_t hashmod = _capacity - 1;
        size_t bucket  = hash(key) & hashmod;

        for (size_t probe = 0; probe <= hashmod; ++probe) {
            item_t& probe_item = _items[bucket];

            if (probe_item.key == key || probe_item.key == 0) return &probe_item;

            // hash collision, quadratic probing
            bucket = (bucket + probe + 1) & hashmod;
        }

        assert(false && "Hash table is full");    // unreachable
        return 0;
    }

    static PUGI__UNSIGNED_OVERFLOW unsigned int hash(const void* key)
    {
        unsigned int h = static_cast<unsigned int>(reinterpret_cast<uintptr_t>(key));

        // MurmurHash3 32-bit finalizer
        h ^= h >> 16;
        h *= 0x85ebca6bu;
        h ^= h >> 13;
        h *= 0xc2b2ae35u;
        h ^= h >> 16;

        return h;
    }
};

PUGI__FN_NO_INLINE bool compact_hash_table::rehash(size_t count)
{
    size_t capacity = 32;
    while (count >= capacity - capacity / 4) capacity *= 2;

    compact_hash_table rt;
    rt._capacity = capacity;
    rt._items    = static_cast<item_t*>(xml_memory::allocate(sizeof(item_t) * capacity));

    if (!rt._items) return false;

    memset(rt._items, 0, sizeof(item_t) * capacity);

    for (size_t i = 0; i < _capacity; ++i)
        if (_items[i].key) rt.insert(_items[i].key, _items[i].value);

    if (_items) xml_memory::deallocate(_items);

    _capacity = capacity;
    _items    = rt._items;

    assert(_count == rt._count);

    return true;
}

PUGI__NS_END
#    endif

PUGI__NS_BEGIN
#    ifdef PUGIXML_COMPACT
static const uintptr_t xml_memory_block_alignment = 4;
#    else
static const uintptr_t xml_memory_block_alignment = sizeof(void*);
#    endif

// extra metadata bits
static const uintptr_t xml_memory_page_contents_shared_mask = 64;
static const uintptr_t xml_memory_page_name_allocated_mask  = 32;
static const uintptr_t xml_memory_page_value_allocated_mask = 16;
static const uintptr_t xml_memory_page_type_mask            = 15;

// combined masks for string uniqueness
static const uintptr_t xml_memory_page_name_allocated_or_shared_mask =
    xml_memory_page_name_allocated_mask | xml_memory_page_contents_shared_mask;
static const uintptr_t xml_memory_page_value_allocated_or_shared_mask =
    xml_memory_page_value_allocated_mask | xml_memory_page_contents_shared_mask;

#    ifdef PUGIXML_COMPACT
#        define PUGI__GETHEADER_IMPL(object, page, flags)    // unused
#        define PUGI__GETPAGE_IMPL(header) (header).get_page()
#    else
#        define PUGI__GETHEADER_IMPL(object, page, flags) \
            (((reinterpret_cast<char*>(object) - reinterpret_cast<char*>(page)) << 8) | (flags))
// this macro casts pointers through void* to avoid 'cast increases required alignment of target type' warnings
#        define PUGI__GETPAGE_IMPL(header)       \
            static_cast<impl::xml_memory_page*>( \
                const_cast<void*>(static_cast<const void*>(reinterpret_cast<const char*>(&header) - (header >> 8))))
#    endif

#    define PUGI__GETPAGE(n) PUGI__GETPAGE_IMPL((n)->header)
#    define PUGI__NODETYPE(n) static_cast<xml_node_type>((n)->header & impl::xml_memory_page_type_mask)

struct xml_allocator;

struct xml_memory_page
{
    static xml_memory_page* construct(void* memory)
    {
        xml_memory_page* result = static_cast<xml_memory_page*>(memory);

        result->allocator  = 0;
        result->prev       = 0;
        result->next       = 0;
        result->busy_size  = 0;
        result->freed_size = 0;

#    ifdef PUGIXML_COMPACT
        result->compact_string_base   = 0;
        result->compact_shared_parent = 0;
        result->compact_page_marker   = 0;
#    endif

        return result;
    }

    xml_allocator* allocator;

    xml_memory_page* prev;
    xml_memory_page* next;

    size_t busy_size;
    size_t freed_size;

#    ifdef PUGIXML_COMPACT
    char_t*   compact_string_base;
    void*     compact_shared_parent;
    uint32_t* compact_page_marker;
#    endif
};

static const size_t xml_memory_page_size =
#    ifdef PUGIXML_MEMORY_PAGE_SIZE
    (PUGIXML_MEMORY_PAGE_SIZE)
#    else
    32768
#    endif
    - sizeof(xml_memory_page);

struct xml_memory_string_header
{
    uint16_t page_offset;    // offset from page->data
    uint16_t full_size;      // 0 if string occupies whole page
};

struct xml_allocator
{
    xml_allocator(xml_memory_page* root) : _root(root), _busy_size(root->busy_size)
    {
#    ifdef PUGIXML_COMPACT
        _hash = 0;
#    endif
    }

    xml_memory_page* allocate_page(size_t data_size)
    {
        size_t size = sizeof(xml_memory_page) + data_size;

        // allocate block with some alignment, leaving memory for worst-case padding
        void* memory = xml_memory::allocate(size);
        if (!memory) return 0;

        // prepare page structure
        xml_memory_page* page = xml_memory_page::construct(memory);
        assert(page);

        page->allocator = _root->allocator;

        return page;
    }

    static void deallocate_page(xml_memory_page* page)
    {
        xml_memory::deallocate(page);
    }

    void* allocate_memory_oob(size_t size, xml_memory_page*& out_page);

    void* allocate_memory(size_t size, xml_memory_page*& out_page)
    {
        if (PUGI__UNLIKELY(_busy_size + size > xml_memory_page_size)) return allocate_memory_oob(size, out_page);

        void* buf = reinterpret_cast<char*>(_root) + sizeof(xml_memory_page) + _busy_size;

        _busy_size += size;

        out_page = _root;

        return buf;
    }

#    ifdef PUGIXML_COMPACT
    void* allocate_object(size_t size, xml_memory_page*& out_page)
    {
        void* result = allocate_memory(size + sizeof(uint32_t), out_page);
        if (!result) return 0;

        // adjust for marker
        ptrdiff_t offset = static_cast<char*>(result) - reinterpret_cast<char*>(out_page->compact_page_marker);

        if (PUGI__UNLIKELY(static_cast<uintptr_t>(offset) >= 256 * xml_memory_block_alignment)) {
            // insert new marker
            uint32_t* marker = static_cast<uint32_t*>(result);

            *marker                       = static_cast<uint32_t>(reinterpret_cast<char*>(marker) - reinterpret_cast<char*>(out_page));
            out_page->compact_page_marker = marker;

            // since we don't reuse the page space until we reallocate it, we can just pretend that we freed the marker block
            // this will make sure deallocate_memory correctly tracks the size
            out_page->freed_size += sizeof(uint32_t);

            return marker + 1;
        }
        else {
            // roll back uint32_t part
            _busy_size -= sizeof(uint32_t);

            return result;
        }
    }
#    else
    void* allocate_object(size_t size, xml_memory_page*& out_page)
    {
        return allocate_memory(size, out_page);
    }
#    endif

    void deallocate_memory(void* ptr, size_t size, xml_memory_page* page)
    {
        if (page == _root) page->busy_size = _busy_size;

        assert(ptr >= reinterpret_cast<char*>(page) + sizeof(xml_memory_page) &&
               ptr < reinterpret_cast<char*>(page) + sizeof(xml_memory_page) + page->busy_size);
        (void)!ptr;

        page->freed_size += size;
        assert(page->freed_size <= page->busy_size);

        if (page->freed_size == page->busy_size) {
            if (page->next == 0) {
                assert(_root == page);

                // top page freed, just reset sizes
                page->busy_size  = 0;
                page->freed_size = 0;

#    ifdef PUGIXML_COMPACT
                // reset compact state to maximize efficiency
                page->compact_string_base   = 0;
                page->compact_shared_parent = 0;
                page->compact_page_marker   = 0;
#    endif

                _busy_size = 0;
            }
            else {
                assert(_root != page);
                assert(page->prev);

                // remove from the list
                page->prev->next = page->next;
                page->next->prev = page->prev;

                // deallocate
                deallocate_page(page);
            }
        }
    }

    char_t* allocate_string(size_t length)
    {
        static const size_t max_encoded_offset = (1 << 16) * xml_memory_block_alignment;

        PUGI__STATIC_ASSERT(xml_memory_page_size <= max_encoded_offset);

        // allocate memory for string and header block
        size_t size = sizeof(xml_memory_string_header) + length * sizeof(char_t);

        // round size up to block alignment boundary
        size_t full_size = (size + (xml_memory_block_alignment - 1)) & ~(xml_memory_block_alignment - 1);

        xml_memory_page*          page;
        xml_memory_string_header* header = static_cast<xml_memory_string_header*>(allocate_memory(full_size, page));

        if (!header) return 0;

        // setup header
        ptrdiff_t page_offset = reinterpret_cast<char*>(header) - reinterpret_cast<char*>(page) - sizeof(xml_memory_page);

        assert(page_offset % xml_memory_block_alignment == 0);
        assert(page_offset >= 0 && static_cast<size_t>(page_offset) < max_encoded_offset);
        header->page_offset = static_cast<uint16_t>(static_cast<size_t>(page_offset) / xml_memory_block_alignment);

        // full_size == 0 for large strings that occupy the whole page
        assert(full_size % xml_memory_block_alignment == 0);
        assert(full_size < max_encoded_offset || (page->busy_size == full_size && page_offset == 0));
        header->full_size = static_cast<uint16_t>(full_size < max_encoded_offset ? full_size / xml_memory_block_alignment : 0);

        // round-trip through void* to avoid 'cast increases required alignment of target type' warning
        // header is guaranteed a pointer-sized alignment, which should be enough for char_t
        return static_cast<char_t*>(static_cast<void*>(header + 1));
    }

    void deallocate_string(char_t* string)
    {
        // this function casts pointers through void* to avoid 'cast increases required alignment of target type' warnings
        // we're guaranteed the proper (pointer-sized) alignment on the input string if it was allocated via allocate_string

        // get header
        xml_memory_string_header* header = static_cast<xml_memory_string_header*>(static_cast<void*>(string)) - 1;
        assert(header);

        // deallocate
        size_t           page_offset = sizeof(xml_memory_page) + header->page_offset * xml_memory_block_alignment;
        xml_memory_page* page = reinterpret_cast<xml_memory_page*>(static_cast<void*>(reinterpret_cast<char*>(header) - page_offset));

        // if full_size == 0 then this string occupies the whole page
        size_t full_size = header->full_size == 0 ? page->busy_size : header->full_size * xml_memory_block_alignment;

        deallocate_memory(header, full_size, page);
    }

    bool reserve()
    {
#    ifdef PUGIXML_COMPACT
        return _hash->reserve();
#    else
        return true;
#    endif
    }

    xml_memory_page* _root;
    size_t           _busy_size;

#    ifdef PUGIXML_COMPACT
    compact_hash_table* _hash;
#    endif
};

PUGI__FN_NO_INLINE void* xml_allocator::allocate_memory_oob(size_t size, xml_memory_page*& out_page)
{
    const size_t large_allocation_threshold = xml_memory_page_size / 4;

    xml_memory_page* page = allocate_page(size <= large_allocation_threshold ? xml_memory_page_size : size);
    out_page              = page;

    if (!page) return 0;

    if (size <= large_allocation_threshold) {
        _root->busy_size = _busy_size;

        // insert page at the end of linked list
        page->prev  = _root;
        _root->next = page;
        _root       = page;

        _busy_size = size;
    }
    else {
        // insert page before the end of linked list, so that it is deleted as soon as possible
        // the last page is not deleted even if it's empty (see deallocate_memory)
        assert(_root->prev);

        page->prev = _root->prev;
        page->next = _root;

        _root->prev->next = page;
        _root->prev       = page;

        page->busy_size = size;
    }

    return reinterpret_cast<char*>(page) + sizeof(xml_memory_page);
}
PUGI__NS_END

#    ifdef PUGIXML_COMPACT
PUGI__NS_BEGIN
static const uintptr_t compact_alignment_log2 = 2;
static const uintptr_t compact_alignment      = 1 << compact_alignment_log2;

class compact_header
{
public:
    compact_header(xml_memory_page* page, unsigned int flags)
    {
        PUGI__STATIC_ASSERT(xml_memory_block_alignment == compact_alignment);

        ptrdiff_t offset = (reinterpret_cast<char*>(this) - reinterpret_cast<char*>(page->compact_page_marker));
        assert(offset % compact_alignment == 0 && static_cast<uintptr_t>(offset) < 256 * compact_alignment);

        _page  = static_cast<unsigned char>(offset >> compact_alignment_log2);
        _flags = static_cast<unsigned char>(flags);
    }

    void operator&=(uintptr_t mod)
    {
        _flags &= static_cast<unsigned char>(mod);
    }

    void operator|=(uintptr_t mod)
    {
        _flags |= static_cast<unsigned char>(mod);
    }

    uintptr_t operator&(uintptr_t mod) const
    {
        return _flags & mod;
    }

    xml_memory_page* get_page() const
    {
        // round-trip through void* to silence 'cast increases required alignment of target type' warnings
        const char* page_marker = reinterpret_cast<const char*>(this) - (_page << compact_alignment_log2);
        const char* page        = page_marker - *reinterpret_cast<const uint32_t*>(static_cast<const void*>(page_marker));

        return const_cast<xml_memory_page*>(reinterpret_cast<const xml_memory_page*>(static_cast<const void*>(page)));
    }

private:
    unsigned char _page;
    unsigned char _flags;
};

PUGI__FN xml_memory_page* compact_get_page(const void* object, int header_offset)
{
    const compact_header* header = reinterpret_cast<const compact_header*>(static_cast<const char*>(object) - header_offset);

    return header->get_page();
}

template<int header_offset, typename T>
PUGI__FN_NO_INLINE T* compact_get_value(const void* object)
{
    return static_cast<T*>(compact_get_page(object, header_offset)->allocator->_hash->find(object));
}

template<int header_offset, typename T>
PUGI__FN_NO_INLINE void compact_set_value(const void* object, T* value)
{
    compact_get_page(object, header_offset)->allocator->_hash->insert(object, value);
}

template<typename T, int header_offset, int start = -126>
class compact_pointer
{
public:
    compact_pointer() : _data(0) {}

    void operator=(const compact_pointer& rhs)
    {
        *this = rhs + 0;
    }

    void operator=(T* value)
    {
        if (value) {
            // value is guaranteed to be compact-aligned; 'this' is not
            // our decoding is based on 'this' aligned to compact alignment downwards (see operator T*)
            // so for negative offsets (e.g. -3) we need to adjust the diff by compact_alignment - 1 to
            // compensate for arithmetic shift rounding for negative values
            ptrdiff_t diff   = reinterpret_cast<char*>(value) - reinterpret_cast<char*>(this);
            ptrdiff_t offset = ((diff + int(compact_alignment - 1)) >> compact_alignment_log2) - start;

            if (static_cast<uintptr_t>(offset) <= 253)
                _data = static_cast<unsigned char>(offset + 1);
            else {
                compact_set_value<header_offset>(this, value);

                _data = 255;
            }
        }
        else
            _data = 0;
    }

    operator T*() const
    {
        if (_data) {
            if (_data < 255) {
                uintptr_t base = reinterpret_cast<uintptr_t>(this) & ~(compact_alignment - 1);

                return reinterpret_cast<T*>(base + (_data - 1 + start) * compact_alignment);
            }
            else
                return compact_get_value<header_offset, T>(this);
        }
        else
            return 0;
    }

    T* operator->() const
    {
        return *this;
    }

private:
    unsigned char _data;
};

template<typename T, int header_offset>
class compact_pointer_parent
{
public:
    compact_pointer_parent() : _data(0) {}

    void operator=(const compact_pointer_parent& rhs)
    {
        *this = rhs + 0;
    }

    void operator=(T* value)
    {
        if (value) {
            // value is guaranteed to be compact-aligned; 'this' is not
            // our decoding is based on 'this' aligned to compact alignment downwards (see operator T*)
            // so for negative offsets (e.g. -3) we need to adjust the diff by compact_alignment - 1 to
            // compensate for arithmetic shift behavior for negative values
            ptrdiff_t diff   = reinterpret_cast<char*>(value) - reinterpret_cast<char*>(this);
            ptrdiff_t offset = ((diff + int(compact_alignment - 1)) >> compact_alignment_log2) + 65533;

            if (static_cast<uintptr_t>(offset) <= 65533) {
                _data = static_cast<unsigned short>(offset + 1);
            }
            else {
                xml_memory_page* page = compact_get_page(this, header_offset);

                if (PUGI__UNLIKELY(page->compact_shared_parent == 0)) page->compact_shared_parent = value;

                if (page->compact_shared_parent == value) {
                    _data = 65534;
                }
                else {
                    compact_set_value<header_offset>(this, value);

                    _data = 65535;
                }
            }
        }
        else {
            _data = 0;
        }
    }

    operator T*() const
    {
        if (_data) {
            if (_data < 65534) {
                uintptr_t base = reinterpret_cast<uintptr_t>(this) & ~(compact_alignment - 1);

                return reinterpret_cast<T*>(base + (_data - 1 - 65533) * compact_alignment);
            }
            else if (_data == 65534)
                return static_cast<T*>(compact_get_page(this, header_offset)->compact_shared_parent);
            else
                return compact_get_value<header_offset, T>(this);
        }
        else
            return 0;
    }

    T* operator->() const
    {
        return *this;
    }

private:
    uint16_t _data;
};

template<int header_offset, int base_offset>
class compact_string
{
public:
    compact_string() : _data(0) {}

    void operator=(const compact_string& rhs)
    {
        *this = rhs + 0;
    }

    void operator=(char_t* value)
    {
        if (value) {
            xml_memory_page* page = compact_get_page(this, header_offset);

            if (PUGI__UNLIKELY(page->compact_string_base == 0)) page->compact_string_base = value;

            ptrdiff_t offset = value - page->compact_string_base;

            if (static_cast<uintptr_t>(offset) < (65535 << 7)) {
                // round-trip through void* to silence 'cast increases required alignment of target type' warnings
                uint16_t* base = reinterpret_cast<uint16_t*>(static_cast<void*>(reinterpret_cast<char*>(this) - base_offset));

                if (*base == 0) {
                    *base = static_cast<uint16_t>((offset >> 7) + 1);
                    _data = static_cast<unsigned char>((offset & 127) + 1);
                }
                else {
                    ptrdiff_t remainder = offset - ((*base - 1) << 7);

                    if (static_cast<uintptr_t>(remainder) <= 253) {
                        _data = static_cast<unsigned char>(remainder + 1);
                    }
                    else {
                        compact_set_value<header_offset>(this, value);

                        _data = 255;
                    }
                }
            }
            else {
                compact_set_value<header_offset>(this, value);

                _data = 255;
            }
        }
        else {
            _data = 0;
        }
    }

    operator char_t*() const
    {
        if (_data) {
            if (_data < 255) {
                xml_memory_page* page = compact_get_page(this, header_offset);

                // round-trip through void* to silence 'cast increases required alignment of target type' warnings
                const uint16_t* base =
                    reinterpret_cast<const uint16_t*>(static_cast<const void*>(reinterpret_cast<const char*>(this) - base_offset));
                assert(*base);

                ptrdiff_t offset = ((*base - 1) << 7) + (_data - 1);

                return page->compact_string_base + offset;
            }
            else {
                return compact_get_value<header_offset, char_t>(this);
            }
        }
        else
            return 0;
    }

private:
    unsigned char _data;
};
PUGI__NS_END
#    endif

#    ifdef PUGIXML_COMPACT
namespace pugi
{
    struct xml_attribute_struct
    {
        xml_attribute_struct(impl::xml_memory_page* page) : header(page, 0), namevalue_base(0)
        {
            PUGI__STATIC_ASSERT(sizeof(xml_attribute_struct) == 8);
        }

        impl::compact_header header;

        uint16_t namevalue_base;

        impl::compact_string<4, 2> name;
        impl::compact_string<5, 3> value;

        impl::compact_pointer<xml_attribute_struct, 6>    prev_attribute_c;
        impl::compact_pointer<xml_attribute_struct, 7, 0> next_attribute;
    };

    struct xml_node_struct
    {
        xml_node_struct(impl::xml_memory_page* page, xml_node_type type) : header(page, type), namevalue_base(0)
        {
            PUGI__STATIC_ASSERT(sizeof(xml_node_struct) == 12);
        }

        impl::compact_header header;

        uint16_t namevalue_base;

        impl::compact_string<4, 2> name;
        impl::compact_string<5, 3> value;

        impl::compact_pointer_parent<xml_node_struct, 6> parent;

        impl::compact_pointer<xml_node_struct, 8, 0> first_child;

        impl::compact_pointer<xml_node_struct, 9>     prev_sibling_c;
        impl::compact_pointer<xml_node_struct, 10, 0> next_sibling;

        impl::compact_pointer<xml_attribute_struct, 11, 0> first_attribute;
    };
}    // namespace pugi
#    else
namespace pugi
{
    struct xml_attribute_struct
    {
        xml_attribute_struct(impl::xml_memory_page* page) : name(0), value(0), prev_attribute_c(0), next_attribute(0)
        {
            header = PUGI__GETHEADER_IMPL(this, page, 0);
        }

        uintptr_t header;

        char_t* name;
        char_t* value;

        xml_attribute_struct* prev_attribute_c;
        xml_attribute_struct* next_attribute;
    };

    struct xml_node_struct
    {
        xml_node_struct(impl::xml_memory_page* page, xml_node_type type)
            : name(0),
              value(0),
              parent(0),
              first_child(0),
              prev_sibling_c(0),
              next_sibling(0),
              first_attribute(0)
        {
            header = PUGI__GETHEADER_IMPL(this, page, type);
        }

        uintptr_t header;

        char_t* name;
        char_t* value;

        xml_node_struct* parent;

        xml_node_struct* first_child;

        xml_node_struct* prev_sibling_c;
        xml_node_struct* next_sibling;

        xml_attribute_struct* first_attribute;
    };
}    // namespace pugi
#    endif

PUGI__NS_BEGIN
struct xml_extra_buffer
{
    char_t*           buffer;
    xml_extra_buffer* next;
};

struct xml_document_struct : public xml_node_struct, public xml_allocator
{
    xml_document_struct(xml_memory_page* page) : xml_node_struct(page, node_document), xml_allocator(page), buffer(0), extra_buffers(0) {}

    const char_t* buffer;

    xml_extra_buffer* extra_buffers;

#    ifdef PUGIXML_COMPACT
    compact_hash_table hash;
#    endif
};

template<typename Object>
inline xml_allocator& get_allocator(const Object* object)
{
    assert(object);

    return *PUGI__GETPAGE(object)->allocator;
}

template<typename Object>
inline xml_document_struct& get_document(const Object* object)
{
    assert(object);

    return *static_cast<xml_document_struct*>(PUGI__GETPAGE(object)->allocator);
}
PUGI__NS_END

// Low-level DOM operations
PUGI__NS_BEGIN
inline xml_attribute_struct* allocate_attribute(xml_allocator& alloc)
{
    xml_memory_page* page;
    void*            memory = alloc.allocate_object(sizeof(xml_attribute_struct), page);
    if (!memory) return 0;

    return new (memory) xml_attribute_struct(page);
}

inline xml_node_struct* allocate_node(xml_allocator& alloc, xml_node_type type)
{
    xml_memory_page* page;
    void*            memory = alloc.allocate_object(sizeof(xml_node_struct), page);
    if (!memory) return 0;

    return new (memory) xml_node_struct(page, type);
}

inline void destroy_attribute(xml_attribute_struct* a, xml_allocator& alloc)
{
    if (a->header & impl::xml_memory_page_name_allocated_mask) alloc.deallocate_string(a->name);

    if (a->header & impl::xml_memory_page_value_allocated_mask) alloc.deallocate_string(a->value);

    alloc.deallocate_memory(a, sizeof(xml_attribute_struct), PUGI__GETPAGE(a));
}

inline void destroy_node(xml_node_struct* n, xml_allocator& alloc)
{
    if (n->header & impl::xml_memory_page_name_allocated_mask) alloc.deallocate_string(n->name);

    if (n->header & impl::xml_memory_page_value_allocated_mask) alloc.deallocate_string(n->value);

    for (xml_attribute_struct* attr = n->first_attribute; attr;) {
        xml_attribute_struct* next = attr->next_attribute;

        destroy_attribute(attr, alloc);

        attr = next;
    }

    for (xml_node_struct* child = n->first_child; child;) {
        xml_node_struct* next = child->next_sibling;

        destroy_node(child, alloc);

        child = next;
    }

    alloc.deallocate_memory(n, sizeof(xml_node_struct), PUGI__GETPAGE(n));
}

inline void append_node(xml_node_struct* child, xml_node_struct* node)
{
    child->parent = node;

    xml_node_struct* head = node->first_child;

    if (head) {
        xml_node_struct* tail = head->prev_sibling_c;

        tail->next_sibling    = child;
        child->prev_sibling_c = tail;
        head->prev_sibling_c  = child;
    }
    else {
        node->first_child     = child;
        child->prev_sibling_c = child;
    }
}

inline void prepend_node(xml_node_struct* child, xml_node_struct* node)
{
    child->parent = node;

    xml_node_struct* head = node->first_child;

    if (head) {
        child->prev_sibling_c = head->prev_sibling_c;
        head->prev_sibling_c  = child;
    }
    else
        child->prev_sibling_c = child;

    child->next_sibling = head;
    node->first_child   = child;
}

inline void insert_node_after(xml_node_struct* child, xml_node_struct* node)
{
    xml_node_struct* parent = node->parent;

    child->parent = parent;

    if (node->next_sibling)
        node->next_sibling->prev_sibling_c = child;
    else
        parent->first_child->prev_sibling_c = child;

    child->next_sibling   = node->next_sibling;
    child->prev_sibling_c = node;

    node->next_sibling = child;
}

inline void insert_node_before(xml_node_struct* child, xml_node_struct* node)
{
    xml_node_struct* parent = node->parent;

    child->parent = parent;

    if (node->prev_sibling_c->next_sibling)
        node->prev_sibling_c->next_sibling = child;
    else
        parent->first_child = child;

    child->prev_sibling_c = node->prev_sibling_c;
    child->next_sibling   = node;

    node->prev_sibling_c = child;
}

inline void remove_node(xml_node_struct* node)
{
    xml_node_struct* parent = node->parent;

    if (node->next_sibling)
        node->next_sibling->prev_sibling_c = node->prev_sibling_c;
    else
        parent->first_child->prev_sibling_c = node->prev_sibling_c;

    if (node->prev_sibling_c->next_sibling)
        node->prev_sibling_c->next_sibling = node->next_sibling;
    else
        parent->first_child = node->next_sibling;

    node->parent         = 0;
    node->prev_sibling_c = 0;
    node->next_sibling   = 0;
}

inline void append_attribute(xml_attribute_struct* attr, xml_node_struct* node)
{
    xml_attribute_struct* head = node->first_attribute;

    if (head) {
        xml_attribute_struct* tail = head->prev_attribute_c;

        tail->next_attribute   = attr;
        attr->prev_attribute_c = tail;
        head->prev_attribute_c = attr;
    }
    else {
        node->first_attribute  = attr;
        attr->prev_attribute_c = attr;
    }
}

inline void prepend_attribute(xml_attribute_struct* attr, xml_node_struct* node)
{
    xml_attribute_struct* head = node->first_attribute;

    if (head) {
        attr->prev_attribute_c = head->prev_attribute_c;
        head->prev_attribute_c = attr;
    }
    else
        attr->prev_attribute_c = attr;

    attr->next_attribute  = head;
    node->first_attribute = attr;
}

inline void insert_attribute_after(xml_attribute_struct* attr, xml_attribute_struct* place, xml_node_struct* node)
{
    if (place->next_attribute)
        place->next_attribute->prev_attribute_c = attr;
    else
        node->first_attribute->prev_attribute_c = attr;

    attr->next_attribute   = place->next_attribute;
    attr->prev_attribute_c = place;
    place->next_attribute  = attr;
}

inline void insert_attribute_before(xml_attribute_struct* attr, xml_attribute_struct* place, xml_node_struct* node)
{
    if (place->prev_attribute_c->next_attribute)
        place->prev_attribute_c->next_attribute = attr;
    else
        node->first_attribute = attr;

    attr->prev_attribute_c  = place->prev_attribute_c;
    attr->next_attribute    = place;
    place->prev_attribute_c = attr;
}

inline void remove_attribute(xml_attribute_struct* attr, xml_node_struct* node)
{
    if (attr->next_attribute)
        attr->next_attribute->prev_attribute_c = attr->prev_attribute_c;
    else
        node->first_attribute->prev_attribute_c = attr->prev_attribute_c;

    if (attr->prev_attribute_c->next_attribute)
        attr->prev_attribute_c->next_attribute = attr->next_attribute;
    else
        node->first_attribute = attr->next_attribute;

    attr->prev_attribute_c = 0;
    attr->next_attribute   = 0;
}

PUGI__FN_NO_INLINE xml_node_struct* append_new_node(xml_node_struct* node, xml_allocator& alloc, xml_node_type type = node_element)
{
    if (!alloc.reserve()) return 0;

    xml_node_struct* child = allocate_node(alloc, type);
    if (!child) return 0;

    append_node(child, node);

    return child;
}

PUGI__FN_NO_INLINE xml_attribute_struct* append_new_attribute(xml_node_struct* node, xml_allocator& alloc)
{
    if (!alloc.reserve()) return 0;

    xml_attribute_struct* attr = allocate_attribute(alloc);
    if (!attr) return 0;

    append_attribute(attr, node);

    return attr;
}
PUGI__NS_END

// Helper classes for code generation
PUGI__NS_BEGIN
struct opt_false
{
    enum { value = 0 };
};

struct opt_true
{
    enum { value = 1 };
};
PUGI__NS_END

// Unicode utilities
PUGI__NS_BEGIN
inline uint16_t endian_swap(uint16_t value)
{
    return static_cast<uint16_t>(((value & 0xff) << 8) | (value >> 8));
}

inline uint32_t endian_swap(uint32_t value)
{
    return ((value & 0xff) << 24) | ((value & 0xff00) << 8) | ((value & 0xff0000) >> 8) | (value >> 24);
}

struct utf8_counter
{
    typedef size_t value_type;

    static value_type low(value_type result, uint32_t ch)
    {
        // U+0000..U+007F
        if (ch < 0x80) return result + 1;
        // U+0080..U+07FF
        else if (ch < 0x800)
            return result + 2;
        // U+0800..U+FFFF
        else
            return result + 3;
    }

    static value_type high(value_type result, uint32_t)
    {
        // U+10000..U+10FFFF
        return result + 4;
    }
};

struct utf8_writer
{
    typedef uint8_t* value_type;

    static value_type low(value_type result, uint32_t ch)
    {
        // U+0000..U+007F
        if (ch < 0x80) {
            *result = static_cast<uint8_t>(ch);
            return result + 1;
        }
        // U+0080..U+07FF
        else if (ch < 0x800) {
            result[0] = static_cast<uint8_t>(0xC0 | (ch >> 6));
            result[1] = static_cast<uint8_t>(0x80 | (ch & 0x3F));
            return result + 2;
        }
        // U+0800..U+FFFF
        else {
            result[0] = static_cast<uint8_t>(0xE0 | (ch >> 12));
            result[1] = static_cast<uint8_t>(0x80 | ((ch >> 6) & 0x3F));
            result[2] = static_cast<uint8_t>(0x80 | (ch & 0x3F));
            return result + 3;
        }
    }

    static value_type high(value_type result, uint32_t ch)
    {
        // U+10000..U+10FFFF
        result[0] = static_cast<uint8_t>(0xF0 | (ch >> 18));
        result[1] = static_cast<uint8_t>(0x80 | ((ch >> 12) & 0x3F));
        result[2] = static_cast<uint8_t>(0x80 | ((ch >> 6) & 0x3F));
        result[3] = static_cast<uint8_t>(0x80 | (ch & 0x3F));
        return result + 4;
    }

    static value_type any(value_type result, uint32_t ch)
    {
        return (ch < 0x10000) ? low(result, ch) : high(result, ch);
    }
};

struct utf16_counter
{
    typedef size_t value_type;

    static value_type low(value_type result, uint32_t)
    {
        return result + 1;
    }

    static value_type high(value_type result, uint32_t)
    {
        return result + 2;
    }
};

struct utf16_writer
{
    typedef uint16_t* value_type;

    static value_type low(value_type result, uint32_t ch)
    {
        *result = static_cast<uint16_t>(ch);

        return result + 1;
    }

    static value_type high(value_type result, uint32_t ch)
    {
        uint32_t msh = static_cast<uint32_t>(ch - 0x10000) >> 10;
        uint32_t lsh = static_cast<uint32_t>(ch - 0x10000) & 0x3ff;

        result[0] = static_cast<uint16_t>(0xD800 + msh);
        result[1] = static_cast<uint16_t>(0xDC00 + lsh);

        return result + 2;
    }

    static value_type any(value_type result, uint32_t ch)
    {
        return (ch < 0x10000) ? low(result, ch) : high(result, ch);
    }
};

struct utf32_counter
{
    typedef size_t value_type;

    static value_type low(value_type result, uint32_t)
    {
        return result + 1;
    }

    static value_type high(value_type result, uint32_t)
    {
        return result + 1;
    }
};

struct utf32_writer
{
    typedef uint32_t* value_type;

    static value_type low(value_type result, uint32_t ch)
    {
        *result = ch;

        return result + 1;
    }

    static value_type high(value_type result, uint32_t ch)
    {
        *result = ch;

        return result + 1;
    }

    static value_type any(value_type result, uint32_t ch)
    {
        *result = ch;

        return result + 1;
    }
};

struct latin1_writer
{
    typedef uint8_t* value_type;

    static value_type low(value_type result, uint32_t ch)
    {
        *result = static_cast<uint8_t>(ch > 255 ? '?' : ch);

        return result + 1;
    }

    static value_type high(value_type result, uint32_t ch)
    {
        (void)ch;

        *result = '?';

        return result + 1;
    }
};

struct utf8_decoder
{
    typedef uint8_t type;

    template<typename Traits>
    static inline typename Traits::value_type process(const uint8_t* data, size_t size, typename Traits::value_type result, Traits)
    {
        const uint8_t utf8_byte_mask = 0x3f;

        while (size) {
            uint8_t lead = *data;

            // 0xxxxxxx -> U+0000..U+007F
            if (lead < 0x80) {
                result = Traits::low(result, lead);
                data += 1;
                size -= 1;

                // process aligned single-byte (ascii) blocks
                if ((reinterpret_cast<uintptr_t>(data) & 3) == 0) {
                    // round-trip through void* to silence 'cast increases required alignment of target type' warnings
                    while (size >= 4 && (*static_cast<const uint32_t*>(static_cast<const void*>(data)) & 0x80808080) == 0) {
                        result = Traits::low(result, data[0]);
                        result = Traits::low(result, data[1]);
                        result = Traits::low(result, data[2]);
                        result = Traits::low(result, data[3]);
                        data += 4;
                        size -= 4;
                    }
                }
            }
            // 110xxxxx -> U+0080..U+07FF
            else if (static_cast<unsigned int>(lead - 0xC0) < 0x20 && size >= 2 && (data[1] & 0xc0) == 0x80) {
                result = Traits::low(result, ((lead & ~0xC0) << 6) | (data[1] & utf8_byte_mask));
                data += 2;
                size -= 2;
            }
            // 1110xxxx -> U+0800-U+FFFF
            else if (static_cast<unsigned int>(lead - 0xE0) < 0x10 && size >= 3 && (data[1] & 0xc0) == 0x80 && (data[2] & 0xc0) == 0x80) {
                result = Traits::low(result, ((lead & ~0xE0) << 12) | ((data[1] & utf8_byte_mask) << 6) | (data[2] & utf8_byte_mask));
                data += 3;
                size -= 3;
            }
            // 11110xxx -> U+10000..U+10FFFF
            else if (static_cast<unsigned int>(lead - 0xF0) < 0x08 && size >= 4 && (data[1] & 0xc0) == 0x80 && (data[2] & 0xc0) == 0x80 &&
                     (data[3] & 0xc0) == 0x80)
            {
                result = Traits::high(result,
                                      ((lead & ~0xF0) << 18) | ((data[1] & utf8_byte_mask) << 12) | ((data[2] & utf8_byte_mask) << 6) |
                                          (data[3] & utf8_byte_mask));
                data += 4;
                size -= 4;
            }
            // 10xxxxxx or 11111xxx -> invalid
            else {
                data += 1;
                size -= 1;
            }
        }

        return result;
    }
};

template<typename opt_swap>
struct utf16_decoder
{
    typedef uint16_t type;

    template<typename Traits>
    static inline typename Traits::value_type process(const uint16_t* data, size_t size, typename Traits::value_type result, Traits)
    {
        while (size) {
            uint16_t lead = opt_swap::value ? endian_swap(*data) : *data;

            // U+0000..U+D7FF
            if (lead < 0xD800) {
                result = Traits::low(result, lead);
                data += 1;
                size -= 1;
            }
            // U+E000..U+FFFF
            else if (static_cast<unsigned int>(lead - 0xE000) < 0x2000) {
                result = Traits::low(result, lead);
                data += 1;
                size -= 1;
            }
            // surrogate pair lead
            else if (static_cast<unsigned int>(lead - 0xD800) < 0x400 && size >= 2) {
                uint16_t next = opt_swap::value ? endian_swap(data[1]) : data[1];

                if (static_cast<unsigned int>(next - 0xDC00) < 0x400) {
                    result = Traits::high(result, 0x10000 + ((lead & 0x3ff) << 10) + (next & 0x3ff));
                    data += 2;
                    size -= 2;
                }
                else {
                    data += 1;
                    size -= 1;
                }
            }
            else {
                data += 1;
                size -= 1;
            }
        }

        return result;
    }
};

template<typename opt_swap>
struct utf32_decoder
{
    typedef uint32_t type;

    template<typename Traits>
    static inline typename Traits::value_type process(const uint32_t* data, size_t size, typename Traits::value_type result, Traits)
    {
        while (size) {
            uint32_t lead = opt_swap::value ? endian_swap(*data) : *data;

            // U+0000..U+FFFF
            if (lead < 0x10000) {
                result = Traits::low(result, lead);
                data += 1;
                size -= 1;
            }
            // U+10000..U+10FFFF
            else {
                result = Traits::high(result, lead);
                data += 1;
                size -= 1;
            }
        }

        return result;
    }
};

struct latin1_decoder
{
    typedef uint8_t type;

    template<typename Traits>
    static inline typename Traits::value_type process(const uint8_t* data, size_t size, typename Traits::value_type result, Traits)
    {
        while (size) {
            result = Traits::low(result, *data);
            data += 1;
            size -= 1;
        }

        return result;
    }
};

template<size_t size>
struct wchar_selector;

template<>
struct wchar_selector<2>
{
    typedef uint16_t                 type;
    typedef utf16_counter            counter;
    typedef utf16_writer             writer;
    typedef utf16_decoder<opt_false> decoder;
};

template<>
struct wchar_selector<4>
{
    typedef uint32_t                 type;
    typedef utf32_counter            counter;
    typedef utf32_writer             writer;
    typedef utf32_decoder<opt_false> decoder;
};

typedef wchar_selector<sizeof(wchar_t)>::counter wchar_counter;
typedef wchar_selector<sizeof(wchar_t)>::writer  wchar_writer;

struct wchar_decoder
{
    typedef wchar_t type;

    template<typename Traits>
    static inline typename Traits::value_type process(const wchar_t* data, size_t size, typename Traits::value_type result, Traits traits)
    {
        typedef wchar_selector<sizeof(wchar_t)>::decoder decoder;

        return decoder::process(reinterpret_cast<const typename decoder::type*>(data), size, result, traits);
    }
};

#    ifdef PUGIXML_WCHAR_MODE
PUGI__FN void convert_wchar_endian_swap(wchar_t* result, const wchar_t* data, size_t length)
{
    for (size_t i = 0; i < length; ++i)
        result[i] = static_cast<wchar_t>(endian_swap(static_cast<wchar_selector<sizeof(wchar_t)>::type>(data[i])));
}
#    endif
PUGI__NS_END

PUGI__NS_BEGIN
enum chartype_t {
    ct_parse_pcdata  = 1,     // \0, &, \r, <
    ct_parse_attr    = 2,     // \0, &, \r, ', "
    ct_parse_attr_ws = 4,     // \0, &, \r, ', ", \n, tab
    ct_space         = 8,     // \r, \n, space, tab
    ct_parse_cdata   = 16,    // \0, ], >, \r
    ct_parse_comment = 32,    // \0, -, >, \r
    ct_symbol        = 64,    // Any symbol > 127, a-z, A-Z, 0-9, _, :, -, .
    ct_start_symbol  = 128    // Any symbol > 127, a-z, A-Z, _, :
};

static const unsigned char chartype_table[256] = {
    55,  0,   0,   0,   0,   0,   0,   0,   0,   12,  12,  0,   0,   63,  0,   0,      // 0-15
    0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,      // 16-31
    8,   0,   6,   0,   0,   0,   7,   6,   0,   0,   0,   0,   0,   96,  64,  0,      // 32-47
    64,  64,  64,  64,  64,  64,  64,  64,  64,  64,  192, 0,   1,   0,   48,  0,      // 48-63
    0,   192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192,    // 64-79
    192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 0,   0,   16,  0,   192,    // 80-95
    0,   192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192,    // 96-111
    192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 0,   0,   0,   0,   0,      // 112-127

    192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192,    // 128+
    192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192,
    192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192,
    192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192,
    192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192,
    192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192, 192
};

enum chartypex_t {
    ctx_special_pcdata = 1,    // Any symbol >= 0 and < 32 (except \t, \r, \n), &, <, >
    ctx_special_attr   = 2,    // Any symbol >= 0 and < 32, &, <, ", '
    ctx_start_symbol   = 4,    // Any symbol > 127, a-z, A-Z, _
    ctx_digit          = 8,    // 0-9
    ctx_symbol         = 16    // Any symbol > 127, a-z, A-Z, 0-9, _, -, .
};

static const unsigned char chartypex_table[256] = { 3,  3,  3,  3,  3,  3,  3,  3,  3,  2,  2,  3,  3,  2,  3,  3,    // 0-15
                                                    3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,    // 16-31
                                                    0,  0,  2,  0,  0,  0,  3,  2,  0,  0,  0,  0,  0,  16, 16, 0,    // 32-47
                                                    24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 0,  0,  3,  0,  1,  0,    // 48-63

                                                    0,  20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20,    // 64-79
                                                    20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 0,  0,  0,  0,  20,    // 80-95
                                                    0,  20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20,    // 96-111
                                                    20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 0,  0,  0,  0,  0,     // 112-127

                                                    20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20,    // 128+
                                                    20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20,
                                                    20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20,
                                                    20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20,
                                                    20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20,
                                                    20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20,
                                                    20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20 };

#    ifdef PUGIXML_WCHAR_MODE
#        define PUGI__IS_CHARTYPE_IMPL(c, ct, table) \
            ((static_cast<unsigned int>(c) < 128 ? table[static_cast<unsigned int>(c)] : table[128]) & (ct))
#    else
#        define PUGI__IS_CHARTYPE_IMPL(c, ct, table) (table[static_cast<unsigned char>(c)] & (ct))
#    endif

#    define PUGI__IS_CHARTYPE(c, ct) PUGI__IS_CHARTYPE_IMPL(c, ct, chartype_table)
#    define PUGI__IS_CHARTYPEX(c, ct) PUGI__IS_CHARTYPE_IMPL(c, ct, chartypex_table)

PUGI__FN bool is_little_endian()
{
    unsigned int ui = 1;

    return *reinterpret_cast<unsigned char*>(&ui) == 1;
}

PUGI__FN xml_encoding get_wchar_encoding()
{
    PUGI__STATIC_ASSERT(sizeof(wchar_t) == 2 || sizeof(wchar_t) == 4);

    if (sizeof(wchar_t) == 2)
        return is_little_endian() ? encoding_utf16_le : encoding_utf16_be;
    else
        return is_little_endian() ? encoding_utf32_le : encoding_utf32_be;
}

PUGI__FN bool parse_declaration_encoding(const uint8_t* data, size_t size, const uint8_t*& out_encoding, size_t& out_length)
{
#    define PUGI__SCANCHAR(ch)                                      \
        {                                                           \
            if (offset >= size || data[offset] != ch) return false; \
            offset++;                                               \
        }
#    define PUGI__SCANCHARTYPE(ct)                                                 \
        {                                                                          \
            while (offset < size && PUGI__IS_CHARTYPE(data[offset], ct)) offset++; \
        }

    // check if we have a non-empty XML declaration
    if (size < 6 || !((data[0] == '<') & (data[1] == '?') & (data[2] == 'x') & (data[3] == 'm') & (data[4] == 'l') &&
                      PUGI__IS_CHARTYPE(data[5], ct_space)))
        return false;

    // scan XML declaration until the encoding field
    for (size_t i = 6; i + 1 < size; ++i) {
        // declaration can not contain ? in quoted values
        if (data[i] == '?') return false;

        if (data[i] == 'e' && data[i + 1] == 'n') {
            size_t offset = i;

            // encoding follows the version field which can't contain 'en' so this has to be the encoding if XML is well formed
            PUGI__SCANCHAR('e');
            PUGI__SCANCHAR('n');
            PUGI__SCANCHAR('c');
            PUGI__SCANCHAR('o');
            PUGI__SCANCHAR('d');
            PUGI__SCANCHAR('i');
            PUGI__SCANCHAR('n');
            PUGI__SCANCHAR('g');

            // S? = S?
            PUGI__SCANCHARTYPE(ct_space);
            PUGI__SCANCHAR('=');
            PUGI__SCANCHARTYPE(ct_space);

            // the only two valid delimiters are ' and "
            uint8_t delimiter = (offset < size && data[offset] == '"') ? '"' : '\'';

            PUGI__SCANCHAR(delimiter);

            size_t start = offset;

            out_encoding = data + offset;

            PUGI__SCANCHARTYPE(ct_symbol);

            out_length = offset - start;

            PUGI__SCANCHAR(delimiter);

            return true;
        }
    }

    return false;

#    undef PUGI__SCANCHAR
#    undef PUGI__SCANCHARTYPE
}

PUGI__FN xml_encoding guess_buffer_encoding(const uint8_t* data, size_t size)
{
    // skip encoding autodetection if input buffer is too small
    if (size < 4) return encoding_utf8;

    uint8_t d0 = data[0], d1 = data[1], d2 = data[2], d3 = data[3];

    // look for BOM in first few bytes
    if (d0 == 0 && d1 == 0 && d2 == 0xfe && d3 == 0xff) return encoding_utf32_be;
    if (d0 == 0xff && d1 == 0xfe && d2 == 0 && d3 == 0) return encoding_utf32_le;
    if (d0 == 0xfe && d1 == 0xff) return encoding_utf16_be;
    if (d0 == 0xff && d1 == 0xfe) return encoding_utf16_le;
    if (d0 == 0xef && d1 == 0xbb && d2 == 0xbf) return encoding_utf8;

    // look for <, <? or <?xm in various encodings
    if (d0 == 0 && d1 == 0 && d2 == 0 && d3 == 0x3c) return encoding_utf32_be;
    if (d0 == 0x3c && d1 == 0 && d2 == 0 && d3 == 0) return encoding_utf32_le;
    if (d0 == 0 && d1 == 0x3c && d2 == 0 && d3 == 0x3f) return encoding_utf16_be;
    if (d0 == 0x3c && d1 == 0 && d2 == 0x3f && d3 == 0) return encoding_utf16_le;

    // look for utf16 < followed by node name (this may fail, but is better than utf8 since it's zero terminated so early)
    if (d0 == 0 && d1 == 0x3c) return encoding_utf16_be;
    if (d0 == 0x3c && d1 == 0) return encoding_utf16_le;

    // no known BOM detected; parse declaration
    const uint8_t* enc        = 0;
    size_t         enc_length = 0;

    if (d0 == 0x3c && d1 == 0x3f && d2 == 0x78 && d3 == 0x6d && parse_declaration_encoding(data, size, enc, enc_length)) {
        // iso-8859-1 (case-insensitive)
        if (enc_length == 10 && (enc[0] | ' ') == 'i' && (enc[1] | ' ') == 's' && (enc[2] | ' ') == 'o' && enc[3] == '-' && enc[4] == '8' &&
            enc[5] == '8' && enc[6] == '5' && enc[7] == '9' && enc[8] == '-' && enc[9] == '1')
            return encoding_latin1;

        // latin1 (case-insensitive)
        if (enc_length == 6 && (enc[0] | ' ') == 'l' && (enc[1] | ' ') == 'a' && (enc[2] | ' ') == 't' && (enc[3] | ' ') == 'i' &&
            (enc[4] | ' ') == 'n' && enc[5] == '1')
            return encoding_latin1;
    }

    return encoding_utf8;
}

PUGI__FN xml_encoding get_buffer_encoding(xml_encoding encoding, const void* contents, size_t size)
{
    // replace wchar encoding with utf implementation
    if (encoding == encoding_wchar) return get_wchar_encoding();

    // replace utf16 encoding with utf16 with specific endianness
    if (encoding == encoding_utf16) return is_little_endian() ? encoding_utf16_le : encoding_utf16_be;

    // replace utf32 encoding with utf32 with specific endianness
    if (encoding == encoding_utf32) return is_little_endian() ? encoding_utf32_le : encoding_utf32_be;

    // only do autodetection if no explicit encoding is requested
    if (encoding != encoding_auto) return encoding;

    // try to guess encoding (based on XML specification, Appendix F.1)
    const uint8_t* data = static_cast<const uint8_t*>(contents);

    return guess_buffer_encoding(data, size);
}

PUGI__FN bool get_mutable_buffer(char_t*& out_buffer, size_t& out_length, const void* contents, size_t size, bool is_mutable)
{
    size_t length = size / sizeof(char_t);

    if (is_mutable) {
        out_buffer = static_cast<char_t*>(const_cast<void*>(contents));
        out_length = length;
    }
    else {
        char_t* buffer = static_cast<char_t*>(xml_memory::allocate((length + 1) * sizeof(char_t)));
        if (!buffer) return false;

        if (contents)
            memcpy(buffer, contents, length * sizeof(char_t));
        else
            assert(length == 0);

        buffer[length] = 0;

        out_buffer = buffer;
        out_length = length + 1;
    }

    return true;
}

#    ifdef PUGIXML_WCHAR_MODE
PUGI__FN bool need_endian_swap_utf(xml_encoding le, xml_encoding re)
{
    return (le == encoding_utf16_be && re == encoding_utf16_le) || (le == encoding_utf16_le && re == encoding_utf16_be) ||
           (le == encoding_utf32_be && re == encoding_utf32_le) || (le == encoding_utf32_le && re == encoding_utf32_be);
}

PUGI__FN bool convert_buffer_endian_swap(char_t*& out_buffer, size_t& out_length, const void* contents, size_t size, bool is_mutable)
{
    const char_t* data   = static_cast<const char_t*>(contents);
    size_t        length = size / sizeof(char_t);

    if (is_mutable) {
        char_t* buffer = const_cast<char_t*>(data);

        convert_wchar_endian_swap(buffer, data, length);

        out_buffer = buffer;
        out_length = length;
    }
    else {
        char_t* buffer = static_cast<char_t*>(xml_memory::allocate((length + 1) * sizeof(char_t)));
        if (!buffer) return false;

        convert_wchar_endian_swap(buffer, data, length);
        buffer[length] = 0;

        out_buffer = buffer;
        out_length = length + 1;
    }

    return true;
}

template<typename D>
PUGI__FN bool convert_buffer_generic(char_t*& out_buffer, size_t& out_length, const void* contents, size_t size, D)
{
    const typename D::type* data        = static_cast<const typename D::type*>(contents);
    size_t                  data_length = size / sizeof(typename D::type);

    // first pass: get length in wchar_t units
    size_t length = D::process(data, data_length, 0, wchar_counter());

    // allocate buffer of suitable length
    char_t* buffer = static_cast<char_t*>(xml_memory::allocate((length + 1) * sizeof(char_t)));
    if (!buffer) return false;

    // second pass: convert utf16 input to wchar_t
    wchar_writer::value_type obegin = reinterpret_cast<wchar_writer::value_type>(buffer);
    wchar_writer::value_type oend   = D::process(data, data_length, obegin, wchar_writer());

    assert(oend == obegin + length);
    *oend = 0;

    out_buffer = buffer;
    out_length = length + 1;

    return true;
}

PUGI__FN bool
    convert_buffer(char_t*& out_buffer, size_t& out_length, xml_encoding encoding, const void* contents, size_t size, bool is_mutable)
{
    // get native encoding
    xml_encoding wchar_encoding = get_wchar_encoding();

    // fast path: no conversion required
    if (encoding == wchar_encoding) return get_mutable_buffer(out_buffer, out_length, contents, size, is_mutable);

    // only endian-swapping is required
    if (need_endian_swap_utf(encoding, wchar_encoding))
        return convert_buffer_endian_swap(out_buffer, out_length, contents, size, is_mutable);

    // source encoding is utf8
    if (encoding == encoding_utf8) return convert_buffer_generic(out_buffer, out_length, contents, size, utf8_decoder());

    // source encoding is utf16
    if (encoding == encoding_utf16_be || encoding == encoding_utf16_le) {
        xml_encoding native_encoding = is_little_endian() ? encoding_utf16_le : encoding_utf16_be;

        return (native_encoding == encoding) ? convert_buffer_generic(out_buffer, out_length, contents, size, utf16_decoder<opt_false>())
                                             : convert_buffer_generic(out_buffer, out_length, contents, size, utf16_decoder<opt_true>());
    }

    // source encoding is utf32
    if (encoding == encoding_utf32_be || encoding == encoding_utf32_le) {
        xml_encoding native_encoding = is_little_endian() ? encoding_utf32_le : encoding_utf32_be;

        return (native_encoding == encoding) ? convert_buffer_generic(out_buffer, out_length, contents, size, utf32_decoder<opt_false>())
                                             : convert_buffer_generic(out_buffer, out_length, contents, size, utf32_decoder<opt_true>());
    }

    // source encoding is latin1
    if (encoding == encoding_latin1) return convert_buffer_generic(out_buffer, out_length, contents, size, latin1_decoder());

    assert(false && "Invalid encoding");    // unreachable
    return false;
}
#    else
template<typename D>
PUGI__FN bool convert_buffer_generic(char_t*& out_buffer, size_t& out_length, const void* contents, size_t size, D)
{
    const typename D::type* data = static_cast<const typename D::type*>(contents);
    size_t data_length = size / sizeof(typename D::type);

    // first pass: get length in utf8 units
    size_t length = D::process(data, data_length, 0, utf8_counter());

    // allocate buffer of suitable length
    char_t* buffer = static_cast<char_t*>(xml_memory::allocate((length + 1) * sizeof(char_t)));
    if (!buffer) return false;

    // second pass: convert utf16 input to utf8
    uint8_t* obegin = reinterpret_cast<uint8_t*>(buffer);
    uint8_t* oend = D::process(data, data_length, obegin, utf8_writer());

    assert(oend == obegin + length);
    *oend = 0;

    out_buffer = buffer;
    out_length = length + 1;

    return true;
}

PUGI__FN size_t get_latin1_7bit_prefix_length(const uint8_t* data, size_t size)
{
    for (size_t i = 0; i < size; ++i)
        if (data[i] > 127) return i;

    return size;
}

PUGI__FN bool convert_buffer_latin1(char_t*& out_buffer, size_t& out_length, const void* contents, size_t size, bool is_mutable)
{
    const uint8_t* data = static_cast<const uint8_t*>(contents);
    size_t data_length = size;

    // get size of prefix that does not need utf8 conversion
    size_t prefix_length = get_latin1_7bit_prefix_length(data, data_length);
    assert(prefix_length <= data_length);

    const uint8_t* postfix = data + prefix_length;
    size_t postfix_length = data_length - prefix_length;

    // if no conversion is needed, just return the original buffer
    if (postfix_length == 0) return get_mutable_buffer(out_buffer, out_length, contents, size, is_mutable);

    // first pass: get length in utf8 units
    size_t length = prefix_length + latin1_decoder::process(postfix, postfix_length, 0, utf8_counter());

    // allocate buffer of suitable length
    char_t* buffer = static_cast<char_t*>(xml_memory::allocate((length + 1) * sizeof(char_t)));
    if (!buffer) return false;

    // second pass: convert latin1 input to utf8
    memcpy(buffer, data, prefix_length);

    uint8_t* obegin = reinterpret_cast<uint8_t*>(buffer);
    uint8_t* oend = latin1_decoder::process(postfix, postfix_length, obegin + prefix_length, utf8_writer());

    assert(oend == obegin + length);
    *oend = 0;

    out_buffer = buffer;
    out_length = length + 1;

    return true;
}

PUGI__FN bool
    convert_buffer(char_t*& out_buffer, size_t& out_length, xml_encoding encoding, const void* contents, size_t size, bool is_mutable)
{
    // fast path: no conversion required
    if (encoding == encoding_utf8) return get_mutable_buffer(out_buffer, out_length, contents, size, is_mutable);

    // source encoding is utf16
    if (encoding == encoding_utf16_be || encoding == encoding_utf16_le) {
        xml_encoding native_encoding = is_little_endian() ? encoding_utf16_le : encoding_utf16_be;

        return (native_encoding == encoding) ? convert_buffer_generic(out_buffer, out_length, contents, size, utf16_decoder<opt_false>())
                                             : convert_buffer_generic(out_buffer, out_length, contents, size, utf16_decoder<opt_true>());
    }

    // source encoding is utf32
    if (encoding == encoding_utf32_be || encoding == encoding_utf32_le) {
        xml_encoding native_encoding = is_little_endian() ? encoding_utf32_le : encoding_utf32_be;

        return (native_encoding == encoding) ? convert_buffer_generic(out_buffer, out_length, contents, size, utf32_decoder<opt_false>())
                                             : convert_buffer_generic(out_buffer, out_length, contents, size, utf32_decoder<opt_true>());
    }

    // source encoding is latin1
    if (encoding == encoding_latin1) return convert_buffer_latin1(out_buffer, out_length, contents, size, is_mutable);

    assert(false && "Invalid encoding");    // unreachable
    return false;
}
#    endif

PUGI__FN size_t as_utf8_begin(const wchar_t* str, size_t length)
{
    // get length in utf8 characters
    return wchar_decoder::process(str, length, 0, utf8_counter());
}

PUGI__FN void as_utf8_end(char* buffer, size_t size, const wchar_t* str, size_t length)
{
    // convert to utf8
    uint8_t* begin = reinterpret_cast<uint8_t*>(buffer);
    uint8_t* end   = wchar_decoder::process(str, length, begin, utf8_writer());

    assert(begin + size == end);
    (void)!end;
    (void)!size;
}

#    ifndef PUGIXML_NO_STL
PUGI__FN std::string as_utf8_impl(const wchar_t* str, size_t length)
{
    // first pass: get length in utf8 characters
    size_t size = as_utf8_begin(str, length);

    // allocate resulting string
    std::string result;
    result.resize(size);

    // second pass: convert to utf8
    if (size > 0) as_utf8_end(&result[0], size, str, length);

    return result;
}

PUGI__FN std::basic_string<wchar_t> as_wide_impl(const char* str, size_t size)
{
    const uint8_t* data = reinterpret_cast<const uint8_t*>(str);

    // first pass: get length in wchar_t units
    size_t length = utf8_decoder::process(data, size, 0, wchar_counter());

    // allocate resulting string
    std::basic_string<wchar_t> result;
    result.resize(length);

    // second pass: convert to wchar_t
    if (length > 0) {
        wchar_writer::value_type begin = reinterpret_cast<wchar_writer::value_type>(&result[0]);
        wchar_writer::value_type end   = utf8_decoder::process(data, size, begin, wchar_writer());

        assert(begin + length == end);
        (void)!end;
    }

    return result;
}
#    endif

template<typename Header>
inline bool strcpy_insitu_allow(size_t length, const Header& header, uintptr_t header_mask, char_t* target)
{
    // never reuse shared memory
    if (header & xml_memory_page_contents_shared_mask) return false;

    size_t target_length = strlength(target);

    // always reuse document buffer memory if possible
    if ((header & header_mask) == 0) return target_length >= length;

    // reuse heap memory if waste is not too great
    const size_t reuse_threshold = 32;

    return target_length >= length && (target_length < reuse_threshold || target_length - length < target_length / 2);
}

template<typename String, typename Header>
PUGI__FN bool strcpy_insitu(String& dest, Header& header, uintptr_t header_mask, const char_t* source, size_t source_length)
{
    if (source_length == 0) {
        // empty string and null pointer are equivalent, so just deallocate old memory
        xml_allocator* alloc = PUGI__GETPAGE_IMPL(header)->allocator;

        if (header & header_mask) alloc->deallocate_string(dest);

        // mark the string as not allocated
        dest = 0;
        header &= ~header_mask;

        return true;
    }
    else if (dest && strcpy_insitu_allow(source_length, header, header_mask, dest)) {
        // we can reuse old buffer, so just copy the new data (including zero terminator)
        memcpy(dest, source, source_length * sizeof(char_t));
        dest[source_length] = 0;

        return true;
    }
    else {
        xml_allocator* alloc = PUGI__GETPAGE_IMPL(header)->allocator;

        if (!alloc->reserve()) return false;

        // allocate new buffer
        char_t* buf = alloc->allocate_string(source_length + 1);
        if (!buf) return false;

        // copy the string (including zero terminator)
        memcpy(buf, source, source_length * sizeof(char_t));
        buf[source_length] = 0;

        // deallocate old buffer (*after* the above to protect against overlapping memory and/or allocation failures)
        if (header & header_mask) alloc->deallocate_string(dest);

        // the string is now allocated, so set the flag
        dest = buf;
        header |= header_mask;

        return true;
    }
}

struct gap
{
    char_t* end;
    size_t  size;

    gap() : end(0), size(0) {}

    // Push new gap, move s count bytes further (skipping the gap).
    // Collapse previous gap.
    void push(char_t*& s, size_t count)
    {
        if (end)    // there was a gap already; collapse it
        {
            // Move [old_gap_end, new_gap_start) to [old_gap_start, ...)
            assert(s >= end);
            memmove(end - size, end, reinterpret_cast<char*>(s) - reinterpret_cast<char*>(end));
        }

        s += count;    // end of current gap

        // "merge" two gaps
        end = s;
        size += count;
    }

    // Collapse all gaps, return past-the-end pointer
    char_t* flush(char_t* s)
    {
        if (end) {
            // Move [old_gap_end, current_pos) to [old_gap_start, ...)
            assert(s >= end);
            memmove(end - size, end, reinterpret_cast<char*>(s) - reinterpret_cast<char*>(end));

            return s - size;
        }
        else
            return s;
    }
};

PUGI__FN char_t* strconv_escape(char_t* s, gap& g)
{
    char_t* stre = s + 1;

    switch (*stre) {
        case '#':    // &#...
        {
            unsigned int ucsc = 0;

            if (stre[1] == 'x')    // &#x... (hex code)
            {
                stre += 2;

                char_t ch = *stre;

                if (ch == ';') return stre;

                for (;;) {
                    if (static_cast<unsigned int>(ch - '0') <= 9)
                        ucsc = 16 * ucsc + (ch - '0');
                    else if (static_cast<unsigned int>((ch | ' ') - 'a') <= 5)
                        ucsc = 16 * ucsc + ((ch | ' ') - 'a' + 10);
                    else if (ch == ';')
                        break;
                    else    // cancel
                        return stre;

                    ch = *++stre;
                }

                ++stre;
            }
            else    // &#... (dec code)
            {
                char_t ch = *++stre;

                if (ch == ';') return stre;

                for (;;) {
                    if (static_cast<unsigned int>(ch - '0') <= 9)
                        ucsc = 10 * ucsc + (ch - '0');
                    else if (ch == ';')
                        break;
                    else    // cancel
                        return stre;

                    ch = *++stre;
                }

                ++stre;
            }

#    ifdef PUGIXML_WCHAR_MODE
            s = reinterpret_cast<char_t*>(wchar_writer::any(reinterpret_cast<wchar_writer::value_type>(s), ucsc));
#    else
            s = reinterpret_cast<char_t*>(utf8_writer::any(reinterpret_cast<uint8_t*>(s), ucsc));
#    endif

            g.push(s, stre - s);
            return stre;
        }

        case 'a':    // &a
        {
            ++stre;

            if (*stre == 'm')    // &am
            {
                if (*++stre == 'p' && *++stre == ';')    // &amp;
                {
                    *s++ = '&';
                    ++stre;

                    g.push(s, stre - s);
                    return stre;
                }
            }
            else if (*stre == 'p')    // &ap
            {
                if (*++stre == 'o' && *++stre == 's' && *++stre == ';')    // &apos;
                {
                    *s++ = '\'';
                    ++stre;

                    g.push(s, stre - s);
                    return stre;
                }
            }
            break;
        }

        case 'g':    // &g
        {
            if (*++stre == 't' && *++stre == ';')    // &gt;
            {
                *s++ = '>';
                ++stre;

                g.push(s, stre - s);
                return stre;
            }
            break;
        }

        case 'l':    // &l
        {
            if (*++stre == 't' && *++stre == ';')    // &lt;
            {
                *s++ = '<';
                ++stre;

                g.push(s, stre - s);
                return stre;
            }
            break;
        }

        case 'q':    // &q
        {
            if (*++stre == 'u' && *++stre == 'o' && *++stre == 't' && *++stre == ';')    // &quot;
            {
                *s++ = '"';
                ++stre;

                g.push(s, stre - s);
                return stre;
            }
            break;
        }

        default:
            break;
    }

    return stre;
}

// Parser utilities
#    define PUGI__ENDSWITH(c, e) ((c) == (e) || ((c) == 0 && endch == (e)))
#    define PUGI__SKIPWS()                               \
        {                                                \
            while (PUGI__IS_CHARTYPE(*s, ct_space)) ++s; \
        }
#    define PUGI__OPTSET(OPT) (optmsk & (OPT))
#    define PUGI__PUSHNODE(TYPE)                                     \
        {                                                            \
            cursor = append_new_node(cursor, *alloc, TYPE);          \
            if (!cursor) PUGI__THROW_ERROR(status_out_of_memory, s); \
        }
#    define PUGI__POPNODE()          \
        {                            \
            cursor = cursor->parent; \
        }
#    define PUGI__SCANFOR(X)             \
        {                                \
            while (*s != 0 && !(X)) ++s; \
        }
#    define PUGI__SCANWHILE(X) \
        {                      \
            while (X) ++s;     \
        }
#    define PUGI__SCANWHILE_UNROLL(X)       \
        {                                   \
            for (;;) {                      \
                char_t ss = s[0];           \
                if (PUGI__UNLIKELY(!(X))) { \
                    break;                  \
                }                           \
                ss = s[1];                  \
                if (PUGI__UNLIKELY(!(X))) { \
                    s += 1;                 \
                    break;                  \
                }                           \
                ss = s[2];                  \
                if (PUGI__UNLIKELY(!(X))) { \
                    s += 2;                 \
                    break;                  \
                }                           \
                ss = s[3];                  \
                if (PUGI__UNLIKELY(!(X))) { \
                    s += 3;                 \
                    break;                  \
                }                           \
                s += 4;                     \
            }                               \
        }
#    define PUGI__ENDSEG() \
        {                  \
            ch = *s;       \
            *s = 0;        \
            ++s;           \
        }
#    define PUGI__THROW_ERROR(err, m) return error_offset = m, error_status = err, static_cast<char_t*>(0)
#    define PUGI__CHECK_ERROR(err, m)               \
        {                                           \
            if (*s == 0) PUGI__THROW_ERROR(err, m); \
        }

PUGI__FN char_t* strconv_comment(char_t* s, char_t endch)
{
    gap g;

    while (true) {
        PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_comment));

        if (*s == '\r')    // Either a single 0x0d or 0x0d 0x0a pair
        {
            *s++ = '\n';    // replace first one with 0x0a

            if (*s == '\n') g.push(s, 1);
        }
        else if (s[0] == '-' && s[1] == '-' && PUGI__ENDSWITH(s[2], '>'))    // comment ends here
        {
            *g.flush(s) = 0;

            return s + (s[2] == '>' ? 3 : 2);
        }
        else if (*s == 0) {
            return 0;
        }
        else
            ++s;
    }
}

PUGI__FN char_t* strconv_cdata(char_t* s, char_t endch)
{
    gap g;

    while (true) {
        PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_cdata));

        if (*s == '\r')    // Either a single 0x0d or 0x0d 0x0a pair
        {
            *s++ = '\n';    // replace first one with 0x0a

            if (*s == '\n') g.push(s, 1);
        }
        else if (s[0] == ']' && s[1] == ']' && PUGI__ENDSWITH(s[2], '>'))    // CDATA ends here
        {
            *g.flush(s) = 0;

            return s + 1;
        }
        else if (*s == 0) {
            return 0;
        }
        else
            ++s;
    }
}

typedef char_t* (*strconv_pcdata_t)(char_t*);

template<typename opt_trim, typename opt_eol, typename opt_escape>
struct strconv_pcdata_impl
{
    static char_t* parse(char_t* s)
    {
        gap g;

        char_t* begin = s;

        while (true) {
            PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_pcdata));

            if (*s == '<')    // PCDATA ends here
            {
                char_t* end = g.flush(s);

                if (opt_trim::value)
                    while (end > begin && PUGI__IS_CHARTYPE(end[-1], ct_space)) --end;

                *end = 0;

                return s + 1;
            }
            else if (opt_eol::value && *s == '\r')    // Either a single 0x0d or 0x0d 0x0a pair
            {
                *s++ = '\n';    // replace first one with 0x0a

                if (*s == '\n') g.push(s, 1);
            }
            else if (opt_escape::value && *s == '&') {
                s = strconv_escape(s, g);
            }
            else if (*s == 0) {
                char_t* end = g.flush(s);

                if (opt_trim::value)
                    while (end > begin && PUGI__IS_CHARTYPE(end[-1], ct_space)) --end;

                *end = 0;

                return s;
            }
            else
                ++s;
        }
    }
};

PUGI__FN strconv_pcdata_t get_strconv_pcdata(unsigned int optmask)
{
    PUGI__STATIC_ASSERT(parse_escapes == 0x10 && parse_eol == 0x20 && parse_trim_pcdata == 0x0800);

    switch (((optmask >> 4) & 3) |
            ((optmask >> 9) & 4))    // get bitmask for flags (trim eol escapes); this simultaneously checks 3 options from assertion above
    {
        case 0:
            return strconv_pcdata_impl<opt_false, opt_false, opt_false>::parse;
        case 1:
            return strconv_pcdata_impl<opt_false, opt_false, opt_true>::parse;
        case 2:
            return strconv_pcdata_impl<opt_false, opt_true, opt_false>::parse;
        case 3:
            return strconv_pcdata_impl<opt_false, opt_true, opt_true>::parse;
        case 4:
            return strconv_pcdata_impl<opt_true, opt_false, opt_false>::parse;
        case 5:
            return strconv_pcdata_impl<opt_true, opt_false, opt_true>::parse;
        case 6:
            return strconv_pcdata_impl<opt_true, opt_true, opt_false>::parse;
        case 7:
            return strconv_pcdata_impl<opt_true, opt_true, opt_true>::parse;
        default:
            assert(false);
            return 0;    // unreachable
    }
}

typedef char_t* (*strconv_attribute_t)(char_t*, char_t);

template<typename opt_escape>
struct strconv_attribute_impl
{
    static char_t* parse_wnorm(char_t* s, char_t end_quote)
    {
        gap g;

        // trim leading whitespaces
        if (PUGI__IS_CHARTYPE(*s, ct_space)) {
            char_t* str = s;

            do ++str;
            while (PUGI__IS_CHARTYPE(*str, ct_space));

            g.push(s, str - s);
        }

        while (true) {
            PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_attr_ws | ct_space));

            if (*s == end_quote) {
                char_t* str = g.flush(s);

                do *str-- = 0;
                while (PUGI__IS_CHARTYPE(*str, ct_space));

                return s + 1;
            }
            else if (PUGI__IS_CHARTYPE(*s, ct_space)) {
                *s++ = ' ';

                if (PUGI__IS_CHARTYPE(*s, ct_space)) {
                    char_t* str = s + 1;
                    while (PUGI__IS_CHARTYPE(*str, ct_space)) ++str;

                    g.push(s, str - s);
                }
            }
            else if (opt_escape::value && *s == '&') {
                s = strconv_escape(s, g);
            }
            else if (!*s) {
                return 0;
            }
            else
                ++s;
        }
    }

    static char_t* parse_wconv(char_t* s, char_t end_quote)
    {
        gap g;

        while (true) {
            PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_attr_ws));

            if (*s == end_quote) {
                *g.flush(s) = 0;

                return s + 1;
            }
            else if (PUGI__IS_CHARTYPE(*s, ct_space)) {
                if (*s == '\r') {
                    *s++ = ' ';

                    if (*s == '\n') g.push(s, 1);
                }
                else
                    *s++ = ' ';
            }
            else if (opt_escape::value && *s == '&') {
                s = strconv_escape(s, g);
            }
            else if (!*s) {
                return 0;
            }
            else
                ++s;
        }
    }

    static char_t* parse_eol(char_t* s, char_t end_quote)
    {
        gap g;

        while (true) {
            PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_attr));

            if (*s == end_quote) {
                *g.flush(s) = 0;

                return s + 1;
            }
            else if (*s == '\r') {
                *s++ = '\n';

                if (*s == '\n') g.push(s, 1);
            }
            else if (opt_escape::value && *s == '&') {
                s = strconv_escape(s, g);
            }
            else if (!*s) {
                return 0;
            }
            else
                ++s;
        }
    }

    static char_t* parse_simple(char_t* s, char_t end_quote)
    {
        gap g;

        while (true) {
            PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_attr));

            if (*s == end_quote) {
                *g.flush(s) = 0;

                return s + 1;
            }
            else if (opt_escape::value && *s == '&') {
                s = strconv_escape(s, g);
            }
            else if (!*s) {
                return 0;
            }
            else
                ++s;
        }
    }
};

PUGI__FN strconv_attribute_t get_strconv_attribute(unsigned int optmask)
{
    PUGI__STATIC_ASSERT(parse_escapes == 0x10 && parse_eol == 0x20 && parse_wconv_attribute == 0x40 && parse_wnorm_attribute == 0x80);

    switch ((optmask >> 4) &
            15)    // get bitmask for flags (wnorm wconv eol escapes); this simultaneously checks 4 options from assertion above
    {
        case 0:
            return strconv_attribute_impl<opt_false>::parse_simple;
        case 1:
            return strconv_attribute_impl<opt_true>::parse_simple;
        case 2:
            return strconv_attribute_impl<opt_false>::parse_eol;
        case 3:
            return strconv_attribute_impl<opt_true>::parse_eol;
        case 4:
            return strconv_attribute_impl<opt_false>::parse_wconv;
        case 5:
            return strconv_attribute_impl<opt_true>::parse_wconv;
        case 6:
            return strconv_attribute_impl<opt_false>::parse_wconv;
        case 7:
            return strconv_attribute_impl<opt_true>::parse_wconv;
        case 8:
            return strconv_attribute_impl<opt_false>::parse_wnorm;
        case 9:
            return strconv_attribute_impl<opt_true>::parse_wnorm;
        case 10:
            return strconv_attribute_impl<opt_false>::parse_wnorm;
        case 11:
            return strconv_attribute_impl<opt_true>::parse_wnorm;
        case 12:
            return strconv_attribute_impl<opt_false>::parse_wnorm;
        case 13:
            return strconv_attribute_impl<opt_true>::parse_wnorm;
        case 14:
            return strconv_attribute_impl<opt_false>::parse_wnorm;
        case 15:
            return strconv_attribute_impl<opt_true>::parse_wnorm;
        default:
            assert(false);
            return 0;    // unreachable
    }
}

inline xml_parse_result make_parse_result(xml_parse_status status, ptrdiff_t offset = 0)
{
    xml_parse_result result;
    result.status = status;
    result.offset = offset;

    return result;
}

struct xml_parser
{
    xml_allocator*   alloc;
    char_t*          error_offset;
    xml_parse_status error_status;

    xml_parser(xml_allocator* alloc_) : alloc(alloc_), error_offset(0), error_status(status_ok) {}

    // DOCTYPE consists of nested sections of the following possible types:
    // <!-- ... -->, <? ... ?>, "...", '...'
    // <![...]]>
    // <!...>
    // First group can not contain nested groups
    // Second group can contain nested groups of the same type
    // Third group can contain all other groups
    char_t* parse_doctype_primitive(char_t* s)
    {
        if (*s == '"' || *s == '\'') {
            // quoted string
            char_t ch = *s++;
            PUGI__SCANFOR(*s == ch);
            if (!*s) PUGI__THROW_ERROR(status_bad_doctype, s);

            s++;
        }
        else if (s[0] == '<' && s[1] == '?') {
            // <? ... ?>
            s += 2;
            PUGI__SCANFOR(s[0] == '?' && s[1] == '>');    // no need for ENDSWITH because ?> can't terminate proper doctype
            if (!*s) PUGI__THROW_ERROR(status_bad_doctype, s);

            s += 2;
        }
        else if (s[0] == '<' && s[1] == '!' && s[2] == '-' && s[3] == '-') {
            s += 4;
            PUGI__SCANFOR(s[0] == '-' && s[1] == '-' && s[2] == '>');    // no need for ENDSWITH because --> can't terminate proper doctype
            if (!*s) PUGI__THROW_ERROR(status_bad_doctype, s);

            s += 3;
        }
        else
            PUGI__THROW_ERROR(status_bad_doctype, s);

        return s;
    }

    char_t* parse_doctype_ignore(char_t* s)
    {
        size_t depth = 0;

        assert(s[0] == '<' && s[1] == '!' && s[2] == '[');
        s += 3;

        while (*s) {
            if (s[0] == '<' && s[1] == '!' && s[2] == '[') {
                // nested ignore section
                s += 3;
                depth++;
            }
            else if (s[0] == ']' && s[1] == ']' && s[2] == '>') {
                // ignore section end
                s += 3;

                if (depth == 0) return s;

                depth--;
            }
            else
                s++;
        }

        PUGI__THROW_ERROR(status_bad_doctype, s);
    }

    char_t* parse_doctype_group(char_t* s, char_t endch)
    {
        size_t depth = 0;

        assert((s[0] == '<' || s[0] == 0) && s[1] == '!');
        s += 2;

        while (*s) {
            if (s[0] == '<' && s[1] == '!' && s[2] != '-') {
                if (s[2] == '[') {
                    // ignore
                    s = parse_doctype_ignore(s);
                    if (!s) return s;
                }
                else {
                    // some control group
                    s += 2;
                    depth++;
                }
            }
            else if (s[0] == '<' || s[0] == '"' || s[0] == '\'') {
                // unknown tag (forbidden), or some primitive group
                s = parse_doctype_primitive(s);
                if (!s) return s;
            }
            else if (*s == '>') {
                if (depth == 0) return s;

                depth--;
                s++;
            }
            else
                s++;
        }

        if (depth != 0 || endch != '>') PUGI__THROW_ERROR(status_bad_doctype, s);

        return s;
    }

    char_t* parse_exclamation(char_t* s, xml_node_struct* cursor, unsigned int optmsk, char_t endch)
    {
        // parse node contents, starting with exclamation mark
        ++s;

        if (*s == '-')    // '<!-...'
        {
            ++s;

            if (*s == '-')    // '<!--...'
            {
                ++s;

                if (PUGI__OPTSET(parse_comments)) {
                    PUGI__PUSHNODE(node_comment);    // Append a new node on the tree.
                    cursor->value = s;               // Save the offset.
                }

                if (PUGI__OPTSET(parse_eol) && PUGI__OPTSET(parse_comments)) {
                    s = strconv_comment(s, endch);

                    if (!s) PUGI__THROW_ERROR(status_bad_comment, cursor->value);
                }
                else {
                    // Scan for terminating '-->'.
                    PUGI__SCANFOR(s[0] == '-' && s[1] == '-' && PUGI__ENDSWITH(s[2], '>'));
                    PUGI__CHECK_ERROR(status_bad_comment, s);

                    if (PUGI__OPTSET(parse_comments)) *s = 0;    // Zero-terminate this segment at the first terminating '-'.

                    s += (s[2] == '>' ? 3 : 2);    // Step over the '\0->'.
                }
            }
            else
                PUGI__THROW_ERROR(status_bad_comment, s);
        }
        else if (*s == '[') {
            // '<![CDATA[...'
            if (*++s == 'C' && *++s == 'D' && *++s == 'A' && *++s == 'T' && *++s == 'A' && *++s == '[') {
                ++s;

                if (PUGI__OPTSET(parse_cdata)) {
                    PUGI__PUSHNODE(node_cdata);    // Append a new node on the tree.
                    cursor->value = s;             // Save the offset.

                    if (PUGI__OPTSET(parse_eol)) {
                        s = strconv_cdata(s, endch);

                        if (!s) PUGI__THROW_ERROR(status_bad_cdata, cursor->value);
                    }
                    else {
                        // Scan for terminating ']]>'.
                        PUGI__SCANFOR(s[0] == ']' && s[1] == ']' && PUGI__ENDSWITH(s[2], '>'));
                        PUGI__CHECK_ERROR(status_bad_cdata, s);

                        *s++ = 0;    // Zero-terminate this segment.
                    }
                }
                else    // Flagged for discard, but we still have to scan for the terminator.
                {
                    // Scan for terminating ']]>'.
                    PUGI__SCANFOR(s[0] == ']' && s[1] == ']' && PUGI__ENDSWITH(s[2], '>'));
                    PUGI__CHECK_ERROR(status_bad_cdata, s);

                    ++s;
                }

                s += (s[1] == '>' ? 2 : 1);    // Step over the last ']>'.
            }
            else
                PUGI__THROW_ERROR(status_bad_cdata, s);
        }
        else if (s[0] == 'D' && s[1] == 'O' && s[2] == 'C' && s[3] == 'T' && s[4] == 'Y' && s[5] == 'P' && PUGI__ENDSWITH(s[6], 'E')) {
            s -= 2;

            if (cursor->parent) PUGI__THROW_ERROR(status_bad_doctype, s);

            char_t* mark = s + 9;

            s = parse_doctype_group(s, endch);
            if (!s) return s;

            assert((*s == 0 && endch == '>') || *s == '>');
            if (*s) *s++ = 0;

            if (PUGI__OPTSET(parse_doctype)) {
                while (PUGI__IS_CHARTYPE(*mark, ct_space)) ++mark;

                PUGI__PUSHNODE(node_doctype);

                cursor->value = mark;
            }
        }
        else if (*s == 0 && endch == '-')
            PUGI__THROW_ERROR(status_bad_comment, s);
        else if (*s == 0 && endch == '[')
            PUGI__THROW_ERROR(status_bad_cdata, s);
        else
            PUGI__THROW_ERROR(status_unrecognized_tag, s);

        return s;
    }

    char_t* parse_question(char_t* s, xml_node_struct*& ref_cursor, unsigned int optmsk, char_t endch)
    {
        // load into registers
        xml_node_struct* cursor = ref_cursor;
        char_t           ch     = 0;

        // parse node contents, starting with question mark
        ++s;

        // read PI target
        char_t* target = s;

        if (!PUGI__IS_CHARTYPE(*s, ct_start_symbol)) PUGI__THROW_ERROR(status_bad_pi, s);

        PUGI__SCANWHILE(PUGI__IS_CHARTYPE(*s, ct_symbol));
        PUGI__CHECK_ERROR(status_bad_pi, s);

        // determine node type; stricmp / strcasecmp is not portable
        bool declaration = (target[0] | ' ') == 'x' && (target[1] | ' ') == 'm' && (target[2] | ' ') == 'l' && target + 3 == s;

        if (declaration ? PUGI__OPTSET(parse_declaration) : PUGI__OPTSET(parse_pi)) {
            if (declaration) {
                // disallow non top-level declarations
                if (cursor->parent) PUGI__THROW_ERROR(status_bad_pi, s);

                PUGI__PUSHNODE(node_declaration);
            }
            else {
                PUGI__PUSHNODE(node_pi);
            }

            cursor->name = target;

            PUGI__ENDSEG();

            // parse value/attributes
            if (ch == '?') {
                // empty node
                if (!PUGI__ENDSWITH(*s, '>')) PUGI__THROW_ERROR(status_bad_pi, s);
                s += (*s == '>');

                PUGI__POPNODE();
            }
            else if (PUGI__IS_CHARTYPE(ch, ct_space)) {
                PUGI__SKIPWS();

                // scan for tag end
                char_t* value = s;

                PUGI__SCANFOR(s[0] == '?' && PUGI__ENDSWITH(s[1], '>'));
                PUGI__CHECK_ERROR(status_bad_pi, s);

                if (declaration) {
                    // replace ending ? with / so that 'element' terminates properly
                    *s = '/';

                    // we exit from this function with cursor at node_declaration, which is a signal to parse() to go to LOC_ATTRIBUTES
                    s = value;
                }
                else {
                    // store value and step over >
                    cursor->value = value;

                    PUGI__POPNODE();

                    PUGI__ENDSEG();

                    s += (*s == '>');
                }
            }
            else
                PUGI__THROW_ERROR(status_bad_pi, s);
        }
        else {
            // scan for tag end
            PUGI__SCANFOR(s[0] == '?' && PUGI__ENDSWITH(s[1], '>'));
            PUGI__CHECK_ERROR(status_bad_pi, s);

            s += (s[1] == '>' ? 2 : 1);
        }

        // store from registers
        ref_cursor = cursor;

        return s;
    }

    char_t* parse_tree(char_t* s, xml_node_struct* root, unsigned int optmsk, char_t endch)
    {
        strconv_attribute_t strconv_attribute = get_strconv_attribute(optmsk);
        strconv_pcdata_t    strconv_pcdata    = get_strconv_pcdata(optmsk);

        char_t           ch     = 0;
        xml_node_struct* cursor = root;
        char_t*          mark   = s;

        while (*s != 0) {
            if (*s == '<') {
                ++s;

LOC_TAG:
                if (PUGI__IS_CHARTYPE(*s, ct_start_symbol))    // '<#...'
                {
                    PUGI__PUSHNODE(node_element);    // Append a new node to the tree.

                    cursor->name = s;

                    PUGI__SCANWHILE_UNROLL(PUGI__IS_CHARTYPE(ss, ct_symbol));    // Scan for a terminator.
                    PUGI__ENDSEG();                                              // Save char in 'ch', terminate & step over.

                    if (ch == '>') {
                        // end of tag
                    }
                    else if (PUGI__IS_CHARTYPE(ch, ct_space)) {
LOC_ATTRIBUTES:
                        while (true) {
                            PUGI__SKIPWS();    // Eat any whitespace.

                            if (PUGI__IS_CHARTYPE(*s, ct_start_symbol))    // <... #...
                            {
                                xml_attribute_struct* a = append_new_attribute(cursor, *alloc);    // Make space for this attribute.
                                if (!a) PUGI__THROW_ERROR(status_out_of_memory, s);

                                a->name = s;    // Save the offset.

                                PUGI__SCANWHILE_UNROLL(PUGI__IS_CHARTYPE(ss, ct_symbol));    // Scan for a terminator.
                                PUGI__ENDSEG();                                              // Save char in 'ch', terminate & step over.

                                if (PUGI__IS_CHARTYPE(ch, ct_space)) {
                                    PUGI__SKIPWS();    // Eat any whitespace.

                                    ch = *s;
                                    ++s;
                                }

                                if (ch == '=')    // '<... #=...'
                                {
                                    PUGI__SKIPWS();    // Eat any whitespace.

                                    if (*s == '"' || *s == '\'')    // '<... #="...'
                                    {
                                        ch = *s;         // Save quote char to avoid breaking on "''" -or- '""'.
                                        ++s;             // Step over the quote.
                                        a->value = s;    // Save the offset.

                                        s = strconv_attribute(s, ch);

                                        if (!s) PUGI__THROW_ERROR(status_bad_attribute, a->value);

                                        // After this line the loop continues from the start;
                                        // Whitespaces, / and > are ok, symbols and EOF are wrong,
                                        // everything else will be detected
                                        if (PUGI__IS_CHARTYPE(*s, ct_start_symbol)) PUGI__THROW_ERROR(status_bad_attribute, s);
                                    }
                                    else
                                        PUGI__THROW_ERROR(status_bad_attribute, s);
                                }
                                else
                                    PUGI__THROW_ERROR(status_bad_attribute, s);
                            }
                            else if (*s == '/') {
                                ++s;

                                if (*s == '>') {
                                    PUGI__POPNODE();
                                    s++;
                                    break;
                                }
                                else if (*s == 0 && endch == '>') {
                                    PUGI__POPNODE();
                                    break;
                                }
                                else
                                    PUGI__THROW_ERROR(status_bad_start_element, s);
                            }
                            else if (*s == '>') {
                                ++s;

                                break;
                            }
                            else if (*s == 0 && endch == '>') {
                                break;
                            }
                            else
                                PUGI__THROW_ERROR(status_bad_start_element, s);
                        }

                        // !!!
                    }
                    else if (ch == '/')    // '<#.../'
                    {
                        if (!PUGI__ENDSWITH(*s, '>')) PUGI__THROW_ERROR(status_bad_start_element, s);

                        PUGI__POPNODE();    // Pop.

                        s += (*s == '>');
                    }
                    else if (ch == 0) {
                        // we stepped over null terminator, backtrack & handle closing tag
                        --s;

                        if (endch != '>') PUGI__THROW_ERROR(status_bad_start_element, s);
                    }
                    else
                        PUGI__THROW_ERROR(status_bad_start_element, s);
                }
                else if (*s == '/') {
                    ++s;

                    mark = s;

                    char_t* name = cursor->name;
                    if (!name) PUGI__THROW_ERROR(status_end_element_mismatch, mark);

                    while (PUGI__IS_CHARTYPE(*s, ct_symbol)) {
                        if (*s++ != *name++) PUGI__THROW_ERROR(status_end_element_mismatch, mark);
                    }

                    if (*name) {
                        if (*s == 0 && name[0] == endch && name[1] == 0)
                            PUGI__THROW_ERROR(status_bad_end_element, s);
                        else
                            PUGI__THROW_ERROR(status_end_element_mismatch, mark);
                    }

                    PUGI__POPNODE();    // Pop.

                    PUGI__SKIPWS();

                    if (*s == 0) {
                        if (endch != '>') PUGI__THROW_ERROR(status_bad_end_element, s);
                    }
                    else {
                        if (*s != '>') PUGI__THROW_ERROR(status_bad_end_element, s);
                        ++s;
                    }
                }
                else if (*s == '?')    // '<?...'
                {
                    s = parse_question(s, cursor, optmsk, endch);
                    if (!s) return s;

                    assert(cursor);
                    if (PUGI__NODETYPE(cursor) == node_declaration) goto LOC_ATTRIBUTES;
                }
                else if (*s == '!')    // '<!...'
                {
                    s = parse_exclamation(s, cursor, optmsk, endch);
                    if (!s) return s;
                }
                else if (*s == 0 && endch == '?')
                    PUGI__THROW_ERROR(status_bad_pi, s);
                else
                    PUGI__THROW_ERROR(status_unrecognized_tag, s);
            }
            else {
                mark = s;    // Save this offset while searching for a terminator.

                PUGI__SKIPWS();    // Eat whitespace if no genuine PCDATA here.

                if (*s == '<' || !*s) {
                    // We skipped some whitespace characters because otherwise we would take the tag branch instead of PCDATA one
                    assert(mark != s);

                    if (!PUGI__OPTSET(parse_ws_pcdata | parse_ws_pcdata_single) || PUGI__OPTSET(parse_trim_pcdata)) {
                        continue;
                    }
                    else if (PUGI__OPTSET(parse_ws_pcdata_single)) {
                        if (s[0] != '<' || s[1] != '/' || cursor->first_child) continue;
                    }
                }

                if (!PUGI__OPTSET(parse_trim_pcdata)) s = mark;

                if (cursor->parent || PUGI__OPTSET(parse_fragment)) {
                    if (PUGI__OPTSET(parse_embed_pcdata) && cursor->parent && !cursor->first_child && !cursor->value) {
                        cursor->value = s;    // Save the offset.
                    }
                    else {
                        PUGI__PUSHNODE(node_pcdata);    // Append a new node on the tree.

                        cursor->value = s;    // Save the offset.

                        PUGI__POPNODE();    // Pop since this is a standalone.
                    }

                    s = strconv_pcdata(s);

                    if (!*s) break;
                }
                else {
                    PUGI__SCANFOR(*s == '<');    // '...<'
                    if (!*s) break;

                    ++s;
                }

                // We're after '<'
                goto LOC_TAG;
            }
        }

        // check that last tag is closed
        if (cursor != root) PUGI__THROW_ERROR(status_end_element_mismatch, s);

        return s;
    }

#    ifdef PUGIXML_WCHAR_MODE
    static char_t* parse_skip_bom(char_t* s)
    {
        unsigned int bom = 0xfeff;
        return (s[0] == static_cast<wchar_t>(bom)) ? s + 1 : s;
    }
#    else
    static char_t* parse_skip_bom(char_t* s)
    {
        return (s[0] == '\xef' && s[1] == '\xbb' && s[2] == '\xbf') ? s + 3 : s;
    }
#    endif

    static bool has_element_node_siblings(xml_node_struct* node)
    {
        while (node) {
            if (PUGI__NODETYPE(node) == node_element) return true;

            node = node->next_sibling;
        }

        return false;
    }

    static xml_parse_result parse(char_t* buffer, size_t length, xml_document_struct* xmldoc, xml_node_struct* root, unsigned int optmsk)
    {
        // early-out for empty documents
        if (length == 0) return make_parse_result(PUGI__OPTSET(parse_fragment) ? status_ok : status_no_document_element);

        // get last child of the root before parsing
        xml_node_struct* last_root_child = root->first_child ? root->first_child->prev_sibling_c + 0 : 0;

        // create parser on stack
        xml_parser parser(static_cast<xml_allocator*>(xmldoc));

        // save last character and make buffer zero-terminated (speeds up parsing)
        char_t endch       = buffer[length - 1];
        buffer[length - 1] = 0;

        // skip BOM to make sure it does not end up as part of parse output
        char_t* buffer_data = parse_skip_bom(buffer);

        // perform actual parsing
        parser.parse_tree(buffer_data, root, optmsk, endch);

        xml_parse_result result = make_parse_result(parser.error_status, parser.error_offset ? parser.error_offset - buffer : 0);
        assert(result.offset >= 0 && static_cast<size_t>(result.offset) <= length);

        if (result) {
            // since we removed last character, we have to handle the only possible false positive (stray <)
            if (endch == '<') return make_parse_result(status_unrecognized_tag, length - 1);

            // check if there are any element nodes parsed
            xml_node_struct* first_root_child_parsed = last_root_child ? last_root_child->next_sibling + 0 : root->first_child + 0;

            if (!PUGI__OPTSET(parse_fragment) && !has_element_node_siblings(first_root_child_parsed))
                return make_parse_result(status_no_document_element, length - 1);
        }
        else {
            // roll back offset if it occurs on a null terminator in the source buffer
            if (result.offset > 0 && static_cast<size_t>(result.offset) == length - 1 && endch == 0) result.offset--;
        }

        return result;
    }
};

// Output facilities
PUGI__FN xml_encoding get_write_native_encoding()
{
#    ifdef PUGIXML_WCHAR_MODE
    return get_wchar_encoding();
#    else
    return encoding_utf8;
#    endif
}

PUGI__FN xml_encoding get_write_encoding(xml_encoding encoding)
{
    // replace wchar encoding with utf implementation
    if (encoding == encoding_wchar) return get_wchar_encoding();

    // replace utf16 encoding with utf16 with specific endianness
    if (encoding == encoding_utf16) return is_little_endian() ? encoding_utf16_le : encoding_utf16_be;

    // replace utf32 encoding with utf32 with specific endianness
    if (encoding == encoding_utf32) return is_little_endian() ? encoding_utf32_le : encoding_utf32_be;

    // only do autodetection if no explicit encoding is requested
    if (encoding != encoding_auto) return encoding;

    // assume utf8 encoding
    return encoding_utf8;
}

template<typename D, typename T>
PUGI__FN size_t convert_buffer_output_generic(typename T::value_type dest, const char_t* data, size_t length, D, T)
{
    PUGI__STATIC_ASSERT(sizeof(char_t) == sizeof(typename D::type));

    typename T::value_type end = D::process(reinterpret_cast<const typename D::type*>(data), length, dest, T());

    return static_cast<size_t>(end - dest) * sizeof(*dest);
}

template<typename D, typename T>
PUGI__FN size_t convert_buffer_output_generic(typename T::value_type dest, const char_t* data, size_t length, D, T, bool opt_swap)
{
    PUGI__STATIC_ASSERT(sizeof(char_t) == sizeof(typename D::type));

    typename T::value_type end = D::process(reinterpret_cast<const typename D::type*>(data), length, dest, T());

    if (opt_swap) {
        for (typename T::value_type i = dest; i != end; ++i) *i = endian_swap(*i);
    }

    return static_cast<size_t>(end - dest) * sizeof(*dest);
}

#    ifdef PUGIXML_WCHAR_MODE
PUGI__FN size_t get_valid_length(const char_t* data, size_t length)
{
    if (length < 1) return 0;

    // discard last character if it's the lead of a surrogate pair
    return (sizeof(wchar_t) == 2 && static_cast<unsigned int>(static_cast<uint16_t>(data[length - 1]) - 0xD800) < 0x400) ? length - 1
                                                                                                                         : length;
}

PUGI__FN size_t convert_buffer_output(char_t*       r_char,
                                      uint8_t*      r_u8,
                                      uint16_t*     r_u16,
                                      uint32_t*     r_u32,
                                      const char_t* data,
                                      size_t        length,
                                      xml_encoding  encoding)
{
    // only endian-swapping is required
    if (need_endian_swap_utf(encoding, get_wchar_encoding())) {
        convert_wchar_endian_swap(r_char, data, length);

        return length * sizeof(char_t);
    }

    // convert to utf8
    if (encoding == encoding_utf8) return convert_buffer_output_generic(r_u8, data, length, wchar_decoder(), utf8_writer());

    // convert to utf16
    if (encoding == encoding_utf16_be || encoding == encoding_utf16_le) {
        xml_encoding native_encoding = is_little_endian() ? encoding_utf16_le : encoding_utf16_be;

        return convert_buffer_output_generic(r_u16, data, length, wchar_decoder(), utf16_writer(), native_encoding != encoding);
    }

    // convert to utf32
    if (encoding == encoding_utf32_be || encoding == encoding_utf32_le) {
        xml_encoding native_encoding = is_little_endian() ? encoding_utf32_le : encoding_utf32_be;

        return convert_buffer_output_generic(r_u32, data, length, wchar_decoder(), utf32_writer(), native_encoding != encoding);
    }

    // convert to latin1
    if (encoding == encoding_latin1) return convert_buffer_output_generic(r_u8, data, length, wchar_decoder(), latin1_writer());

    assert(false && "Invalid encoding");    // unreachable
    return 0;
}
#    else
PUGI__FN size_t get_valid_length(const char_t* data, size_t length)
{
    if (length < 5) return 0;

    for (size_t i = 1; i <= 4; ++i) {
        uint8_t ch = static_cast<uint8_t>(data[length - i]);

        // either a standalone character or a leading one
        if ((ch & 0xc0) != 0x80) return length - i;
    }

    // there are four non-leading characters at the end, sequence tail is broken so might as well process the whole chunk
    return length;
}

PUGI__FN size_t convert_buffer_output(char_t* /* r_char */,
                                      uint8_t* r_u8,
                                      uint16_t* r_u16,
                                      uint32_t* r_u32,
                                      const char_t* data,
                                      size_t length,
                                      xml_encoding encoding)
{
    if (encoding == encoding_utf16_be || encoding == encoding_utf16_le) {
        xml_encoding native_encoding = is_little_endian() ? encoding_utf16_le : encoding_utf16_be;

        return convert_buffer_output_generic(r_u16, data, length, utf8_decoder(), utf16_writer(), native_encoding != encoding);
    }

    if (encoding == encoding_utf32_be || encoding == encoding_utf32_le) {
        xml_encoding native_encoding = is_little_endian() ? encoding_utf32_le : encoding_utf32_be;

        return convert_buffer_output_generic(r_u32, data, length, utf8_decoder(), utf32_writer(), native_encoding != encoding);
    }

    if (encoding == encoding_latin1) return convert_buffer_output_generic(r_u8, data, length, utf8_decoder(), latin1_writer());

    assert(false && "Invalid encoding");    // unreachable
    return 0;
}
#    endif

class xml_buffered_writer
{
    xml_buffered_writer(const xml_buffered_writer&);
    xml_buffered_writer& operator=(const xml_buffered_writer&);

public:
    xml_buffered_writer(xml_writer& writer_, xml_encoding user_encoding)
        : writer(writer_),
          bufsize(0),
          encoding(get_write_encoding(user_encoding))
    {
        PUGI__STATIC_ASSERT(bufcapacity >= 8);
    }

    size_t flush()
    {
        flush(buffer, bufsize);
        bufsize = 0;
        return 0;
    }

    void flush(const char_t* data, size_t size)
    {
        if (size == 0) return;

        // fast path, just write data
        if (encoding == get_write_native_encoding())
            writer.write(data, size * sizeof(char_t));
        else {
            // convert chunk
            size_t result =
                convert_buffer_output(scratch.data_char, scratch.data_u8, scratch.data_u16, scratch.data_u32, data, size, encoding);
            assert(result <= sizeof(scratch));

            // write data
            writer.write(scratch.data_u8, result);
        }
    }

    void write_direct(const char_t* data, size_t length)
    {
        // flush the remaining buffer contents
        flush();

        // handle large chunks
        if (length > bufcapacity) {
            if (encoding == get_write_native_encoding()) {
                // fast path, can just write data chunk
                writer.write(data, length * sizeof(char_t));
                return;
            }

            // need to convert in suitable chunks
            while (length > bufcapacity) {
                // get chunk size by selecting such number of characters that are guaranteed to fit into scratch buffer
                // and form a complete codepoint sequence (i.e. discard start of last codepoint if necessary)
                size_t chunk_size = get_valid_length(data, bufcapacity);
                assert(chunk_size);

                // convert chunk and write
                flush(data, chunk_size);

                // iterate
                data += chunk_size;
                length -= chunk_size;
            }

            // small tail is copied below
            bufsize = 0;
        }

        memcpy(buffer + bufsize, data, length * sizeof(char_t));
        bufsize += length;
    }

    void write_buffer(const char_t* data, size_t length)
    {
        size_t offset = bufsize;

        if (offset + length <= bufcapacity) {
            memcpy(buffer + offset, data, length * sizeof(char_t));
            bufsize = offset + length;
        }
        else {
            write_direct(data, length);
        }
    }

    void write_string(const char_t* data)
    {
        // write the part of the string that fits in the buffer
        size_t offset = bufsize;

        while (*data && offset < bufcapacity) buffer[offset++] = *data++;

        // write the rest
        if (offset < bufcapacity) {
            bufsize = offset;
        }
        else {
            // backtrack a bit if we have split the codepoint
            size_t length = offset - bufsize;
            size_t extra  = length - get_valid_length(data - length, length);

            bufsize = offset - extra;

            write_direct(data - extra, strlength(data) + extra);
        }
    }

    void write(char_t d0)
    {
        size_t offset = bufsize;
        if (offset > bufcapacity - 1) offset = flush();

        buffer[offset + 0] = d0;
        bufsize            = offset + 1;
    }

    void write(char_t d0, char_t d1)
    {
        size_t offset = bufsize;
        if (offset > bufcapacity - 2) offset = flush();

        buffer[offset + 0] = d0;
        buffer[offset + 1] = d1;
        bufsize            = offset + 2;
    }

    void write(char_t d0, char_t d1, char_t d2)
    {
        size_t offset = bufsize;
        if (offset > bufcapacity - 3) offset = flush();

        buffer[offset + 0] = d0;
        buffer[offset + 1] = d1;
        buffer[offset + 2] = d2;
        bufsize            = offset + 3;
    }

    void write(char_t d0, char_t d1, char_t d2, char_t d3)
    {
        size_t offset = bufsize;
        if (offset > bufcapacity - 4) offset = flush();

        buffer[offset + 0] = d0;
        buffer[offset + 1] = d1;
        buffer[offset + 2] = d2;
        buffer[offset + 3] = d3;
        bufsize            = offset + 4;
    }

    void write(char_t d0, char_t d1, char_t d2, char_t d3, char_t d4)
    {
        size_t offset = bufsize;
        if (offset > bufcapacity - 5) offset = flush();

        buffer[offset + 0] = d0;
        buffer[offset + 1] = d1;
        buffer[offset + 2] = d2;
        buffer[offset + 3] = d3;
        buffer[offset + 4] = d4;
        bufsize            = offset + 5;
    }

    void write(char_t d0, char_t d1, char_t d2, char_t d3, char_t d4, char_t d5)
    {
        size_t offset = bufsize;
        if (offset > bufcapacity - 6) offset = flush();

        buffer[offset + 0] = d0;
        buffer[offset + 1] = d1;
        buffer[offset + 2] = d2;
        buffer[offset + 3] = d3;
        buffer[offset + 4] = d4;
        buffer[offset + 5] = d5;
        bufsize            = offset + 6;
    }

    // utf8 maximum expansion: x4 (-> utf32)
    // utf16 maximum expansion: x2 (-> utf32)
    // utf32 maximum expansion: x1
    enum {
        bufcapacitybytes =
#    ifdef PUGIXML_MEMORY_OUTPUT_STACK
            PUGIXML_MEMORY_OUTPUT_STACK
#    else
            10240
#    endif
        ,
        bufcapacity = bufcapacitybytes / (sizeof(char_t) + 4)
    };

    char_t buffer[bufcapacity];

    union
    {
        uint8_t  data_u8[4 * bufcapacity];
        uint16_t data_u16[2 * bufcapacity];
        uint32_t data_u32[bufcapacity];
        char_t   data_char[bufcapacity];
    } scratch;

    xml_writer&  writer;
    size_t       bufsize;
    xml_encoding encoding;
};

PUGI__FN void text_output_escaped(xml_buffered_writer& writer, const char_t* s, chartypex_t type, unsigned int flags)
{
    while (*s) {
        const char_t* prev = s;

        // While *s is a usual symbol
        PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPEX(ss, type));

        writer.write_buffer(prev, static_cast<size_t>(s - prev));

        switch (*s) {
            case 0:
                break;
            case '&':
                writer.write('&', 'a', 'm', 'p', ';');
                ++s;
                break;
            case '<':
                writer.write('&', 'l', 't', ';');
                ++s;
                break;
            case '>':
                writer.write('&', 'g', 't', ';');
                ++s;
                break;
            case '"':
                if (flags & format_attribute_single_quote)
                    writer.write('"');
                else
                    writer.write('&', 'q', 'u', 'o', 't', ';');
                ++s;
                break;
            case '\'':
                if (flags & format_attribute_single_quote)
                    writer.write('&', 'a', 'p', 'o', 's', ';');
                else
                    writer.write('\'');
                ++s;
                break;
            default:    // s is not a usual symbol
            {
                unsigned int ch = static_cast<unsigned int>(*s++);
                assert(ch < 32);

                if (!(flags & format_skip_control_chars))
                    writer.write('&', '#', static_cast<char_t>((ch / 10) + '0'), static_cast<char_t>((ch % 10) + '0'), ';');
            }
        }
    }
}

PUGI__FN void text_output(xml_buffered_writer& writer, const char_t* s, chartypex_t type, unsigned int flags)
{
    if (flags & format_no_escapes)
        writer.write_string(s);
    else
        text_output_escaped(writer, s, type, flags);
}

PUGI__FN void text_output_cdata(xml_buffered_writer& writer, const char_t* s)
{
    do {
        writer.write('<', '!', '[', 'C', 'D');
        writer.write('A', 'T', 'A', '[');

        const char_t* prev = s;

        // look for ]]> sequence - we can't output it as is since it terminates CDATA
        while (*s && !(s[0] == ']' && s[1] == ']' && s[2] == '>')) ++s;

        // skip ]] if we stopped at ]]>, > will go to the next CDATA section
        if (*s) s += 2;

        writer.write_buffer(prev, static_cast<size_t>(s - prev));

        writer.write(']', ']', '>');
    }
    while (*s);
}

PUGI__FN void text_output_indent(xml_buffered_writer& writer, const char_t* indent, size_t indent_length, unsigned int depth)
{
    switch (indent_length) {
        case 1: {
            for (unsigned int i = 0; i < depth; ++i) writer.write(indent[0]);
            break;
        }

        case 2: {
            for (unsigned int i = 0; i < depth; ++i) writer.write(indent[0], indent[1]);
            break;
        }

        case 3: {
            for (unsigned int i = 0; i < depth; ++i) writer.write(indent[0], indent[1], indent[2]);
            break;
        }

        case 4: {
            for (unsigned int i = 0; i < depth; ++i) writer.write(indent[0], indent[1], indent[2], indent[3]);
            break;
        }

        default: {
            for (unsigned int i = 0; i < depth; ++i) writer.write_buffer(indent, indent_length);
        }
    }
}

PUGI__FN void node_output_comment(xml_buffered_writer& writer, const char_t* s)
{
    writer.write('<', '!', '-', '-');

    while (*s) {
        const char_t* prev = s;

        // look for -\0 or -- sequence - we can't output it since -- is illegal in comment body
        while (*s && !(s[0] == '-' && (s[1] == '-' || s[1] == 0))) ++s;

        writer.write_buffer(prev, static_cast<size_t>(s - prev));

        if (*s) {
            assert(*s == '-');

            writer.write('-', ' ');
            ++s;
        }
    }

    writer.write('-', '-', '>');
}

PUGI__FN void node_output_pi_value(xml_buffered_writer& writer, const char_t* s)
{
    while (*s) {
        const char_t* prev = s;

        // look for ?> sequence - we can't output it since ?> terminates PI
        while (*s && !(s[0] == '?' && s[1] == '>')) ++s;

        writer.write_buffer(prev, static_cast<size_t>(s - prev));

        if (*s) {
            assert(s[0] == '?' && s[1] == '>');

            writer.write('?', ' ', '>');
            s += 2;
        }
    }
}

PUGI__FN void node_output_attributes(xml_buffered_writer& writer,
                                     xml_node_struct*     node,
                                     const char_t*        indent,
                                     size_t               indent_length,
                                     unsigned int         flags,
                                     unsigned int         depth)
{
    const char_t* default_name     = PUGIXML_TEXT(":anonymous");
    const char_t  enquotation_char = (flags & format_attribute_single_quote) ? '\'' : '"';

    for (xml_attribute_struct* a = node->first_attribute; a; a = a->next_attribute) {
        if ((flags & (format_indent_attributes | format_raw)) == format_indent_attributes) {
            writer.write('\n');

            text_output_indent(writer, indent, indent_length, depth + 1);
        }
        else {
            writer.write(' ');
        }

        writer.write_string(a->name ? a->name + 0 : default_name);
        writer.write('=', enquotation_char);

        if (a->value) text_output(writer, a->value, ctx_special_attr, flags);

        writer.write(enquotation_char);
    }
}

PUGI__FN bool node_output_start(xml_buffered_writer& writer,
                                xml_node_struct*     node,
                                const char_t*        indent,
                                size_t               indent_length,
                                unsigned int         flags,
                                unsigned int         depth)
{
    const char_t* default_name = PUGIXML_TEXT(":anonymous");
    const char_t* name         = node->name ? node->name + 0 : default_name;

    writer.write('<');
    writer.write_string(name);

    if (node->first_attribute) node_output_attributes(writer, node, indent, indent_length, flags, depth);

    // element nodes can have value if parse_embed_pcdata was used
    if (!node->value) {
        if (!node->first_child) {
            if (flags & format_no_empty_element_tags) {
                writer.write('>', '<', '/');
                writer.write_string(name);
                writer.write('>');

                return false;
            }
            else {
                if ((flags & format_raw) == 0) writer.write(' ');

                writer.write('/', '>');

                return false;
            }
        }
        else {
            writer.write('>');

            return true;
        }
    }
    else {
        writer.write('>');

        text_output(writer, node->value, ctx_special_pcdata, flags);

        if (!node->first_child) {
            writer.write('<', '/');
            writer.write_string(name);
            writer.write('>');

            return false;
        }
        else {
            return true;
        }
    }
}

PUGI__FN void node_output_end(xml_buffered_writer& writer, xml_node_struct* node)
{
    const char_t* default_name = PUGIXML_TEXT(":anonymous");
    const char_t* name         = node->name ? node->name + 0 : default_name;

    writer.write('<', '/');
    writer.write_string(name);
    writer.write('>');
}

PUGI__FN void node_output_simple(xml_buffered_writer& writer, xml_node_struct* node, unsigned int flags)
{
    const char_t* default_name = PUGIXML_TEXT(":anonymous");

    switch (PUGI__NODETYPE(node)) {
        case node_pcdata:
            text_output(writer, node->value ? node->value + 0 : PUGIXML_TEXT(""), ctx_special_pcdata, flags);
            break;

        case node_cdata:
            text_output_cdata(writer, node->value ? node->value + 0 : PUGIXML_TEXT(""));
            break;

        case node_comment:
            node_output_comment(writer, node->value ? node->value + 0 : PUGIXML_TEXT(""));
            break;

        case node_pi:
            writer.write('<', '?');
            writer.write_string(node->name ? node->name + 0 : default_name);

            if (node->value) {
                writer.write(' ');
                node_output_pi_value(writer, node->value);
            }

            writer.write('?', '>');
            break;

        case node_declaration:
            writer.write('<', '?');
            writer.write_string(node->name ? node->name + 0 : default_name);
            node_output_attributes(writer, node, PUGIXML_TEXT(""), 0, flags | format_raw, 0);
            writer.write('?', '>');
            break;

        case node_doctype:
            writer.write('<', '!', 'D', 'O', 'C');
            writer.write('T', 'Y', 'P', 'E');

            if (node->value) {
                writer.write(' ');
                writer.write_string(node->value);
            }

            writer.write('>');
            break;

        default:
            assert(false && "Invalid node type");    // unreachable
    }
}

enum indent_flags_t { indent_newline = 1, indent_indent = 2 };

PUGI__FN void node_output(xml_buffered_writer& writer, xml_node_struct* root, const char_t* indent, unsigned int flags, unsigned int depth)
{
    size_t indent_length      = ((flags & (format_indent | format_indent_attributes)) && (flags & format_raw) == 0) ? strlength(indent) : 0;
    unsigned int indent_flags = indent_indent;

    xml_node_struct* node = root;

    do {
        assert(node);

        // begin writing current node
        if (PUGI__NODETYPE(node) == node_pcdata || PUGI__NODETYPE(node) == node_cdata) {
            node_output_simple(writer, node, flags);

            indent_flags = 0;
        }
        else {
            if ((indent_flags & indent_newline) && (flags & format_raw) == 0) writer.write('\n');

            if ((indent_flags & indent_indent) && indent_length) text_output_indent(writer, indent, indent_length, depth);

            if (PUGI__NODETYPE(node) == node_element) {
                indent_flags = indent_newline | indent_indent;

                if (node_output_start(writer, node, indent, indent_length, flags, depth)) {
                    // element nodes can have value if parse_embed_pcdata was used
                    if (node->value) indent_flags = 0;

                    node = node->first_child;
                    depth++;
                    continue;
                }
            }
            else if (PUGI__NODETYPE(node) == node_document) {
                indent_flags = indent_indent;

                if (node->first_child) {
                    node = node->first_child;
                    continue;
                }
            }
            else {
                node_output_simple(writer, node, flags);

                indent_flags = indent_newline | indent_indent;
            }
        }

        // continue to the next node
        while (node != root) {
            if (node->next_sibling) {
                node = node->next_sibling;
                break;
            }

            node = node->parent;

            // write closing node
            if (PUGI__NODETYPE(node) == node_element) {
                depth--;

                if ((indent_flags & indent_newline) && (flags & format_raw) == 0) writer.write('\n');

                if ((indent_flags & indent_indent) && indent_length) text_output_indent(writer, indent, indent_length, depth);

                node_output_end(writer, node);

                indent_flags = indent_newline | indent_indent;
            }
        }
    }
    while (node != root);

    if ((indent_flags & indent_newline) && (flags & format_raw) == 0) writer.write('\n');
}

PUGI__FN bool has_declaration(xml_node_struct* node)
{
    for (xml_node_struct* child = node->first_child; child; child = child->next_sibling) {
        xml_node_type type = PUGI__NODETYPE(child);

        if (type == node_declaration) return true;
        if (type == node_element) return false;
    }

    return false;
}

PUGI__FN bool is_attribute_of(xml_attribute_struct* attr, xml_node_struct* node)
{
    for (xml_attribute_struct* a = node->first_attribute; a; a = a->next_attribute)
        if (a == attr) return true;

    return false;
}

PUGI__FN bool allow_insert_attribute(xml_node_type parent)
{
    return parent == node_element || parent == node_declaration;
}

PUGI__FN bool allow_insert_child(xml_node_type parent, xml_node_type child)
{
    if (parent != node_document && parent != node_element) return false;
    if (child == node_document || child == node_null) return false;
    if (parent != node_document && (child == node_declaration || child == node_doctype)) return false;

    return true;
}

PUGI__FN bool allow_move(xml_node parent, xml_node child)
{
    // check that child can be a child of parent
    if (!allow_insert_child(parent.type(), child.type())) return false;

    // check that node is not moved between documents
    if (parent.root() != child.root()) return false;

    // check that new parent is not in the child subtree
    xml_node cur = parent;

    while (cur) {
        if (cur == child) return false;

        cur = cur.parent();
    }

    return true;
}

template<typename String, typename Header>
PUGI__FN void
    node_copy_string(String& dest, Header& header, uintptr_t header_mask, char_t* source, Header& source_header, xml_allocator* alloc)
{
    assert(!dest && (header & header_mask) == 0);

    if (source) {
        if (alloc && (source_header & header_mask) == 0) {
            dest = source;

            // since strcpy_insitu can reuse document buffer memory we need to mark both source and dest as shared
            header |= xml_memory_page_contents_shared_mask;
            source_header |= xml_memory_page_contents_shared_mask;
        }
        else
            strcpy_insitu(dest, header, header_mask, source, strlength(source));
    }
}

PUGI__FN void node_copy_contents(xml_node_struct* dn, xml_node_struct* sn, xml_allocator* shared_alloc)
{
    node_copy_string(dn->name, dn->header, xml_memory_page_name_allocated_mask, sn->name, sn->header, shared_alloc);
    node_copy_string(dn->value, dn->header, xml_memory_page_value_allocated_mask, sn->value, sn->header, shared_alloc);

    for (xml_attribute_struct* sa = sn->first_attribute; sa; sa = sa->next_attribute) {
        xml_attribute_struct* da = append_new_attribute(dn, get_allocator(dn));

        if (da) {
            node_copy_string(da->name, da->header, xml_memory_page_name_allocated_mask, sa->name, sa->header, shared_alloc);
            node_copy_string(da->value, da->header, xml_memory_page_value_allocated_mask, sa->value, sa->header, shared_alloc);
        }
    }
}

PUGI__FN void node_copy_tree(xml_node_struct* dn, xml_node_struct* sn)
{
    xml_allocator& alloc        = get_allocator(dn);
    xml_allocator* shared_alloc = (&alloc == &get_allocator(sn)) ? &alloc : 0;

    node_copy_contents(dn, sn, shared_alloc);

    xml_node_struct* dit = dn;
    xml_node_struct* sit = sn->first_child;

    while (sit && sit != sn) {
        // when a tree is copied into one of the descendants, we need to skip that subtree to avoid an infinite loop
        if (sit != dn) {
            xml_node_struct* copy = append_new_node(dit, alloc, PUGI__NODETYPE(sit));

            if (copy) {
                node_copy_contents(copy, sit, shared_alloc);

                if (sit->first_child) {
                    dit = copy;
                    sit = sit->first_child;
                    continue;
                }
            }
        }

        // continue to the next node
        do {
            if (sit->next_sibling) {
                sit = sit->next_sibling;
                break;
            }

            sit = sit->parent;
            dit = dit->parent;
        }
        while (sit != sn);
    }
}

PUGI__FN void node_copy_attribute(xml_attribute_struct* da, xml_attribute_struct* sa)
{
    xml_allocator& alloc        = get_allocator(da);
    xml_allocator* shared_alloc = (&alloc == &get_allocator(sa)) ? &alloc : 0;

    node_copy_string(da->name, da->header, xml_memory_page_name_allocated_mask, sa->name, sa->header, shared_alloc);
    node_copy_string(da->value, da->header, xml_memory_page_value_allocated_mask, sa->value, sa->header, shared_alloc);
}

inline bool is_text_node(xml_node_struct* node)
{
    xml_node_type type = PUGI__NODETYPE(node);

    return type == node_pcdata || type == node_cdata;
}

// get value with conversion functions
template<typename U>
PUGI__FN PUGI__UNSIGNED_OVERFLOW U string_to_integer(const char_t* value, U minv, U maxv)
{
    U             result = 0;
    const char_t* s      = value;

    while (PUGI__IS_CHARTYPE(*s, ct_space)) s++;

    bool negative = (*s == '-');

    s += (*s == '+' || *s == '-');

    bool overflow = false;

    if (s[0] == '0' && (s[1] | ' ') == 'x') {
        s += 2;

        // since overflow detection relies on length of the sequence skip leading zeros
        while (*s == '0') s++;

        const char_t* start = s;

        for (;;) {
            if (static_cast<unsigned>(*s - '0') < 10)
                result = result * 16 + (*s - '0');
            else if (static_cast<unsigned>((*s | ' ') - 'a') < 6)
                result = result * 16 + ((*s | ' ') - 'a' + 10);
            else
                break;

            s++;
        }

        size_t digits = static_cast<size_t>(s - start);

        overflow = digits > sizeof(U) * 2;
    }
    else {
        // since overflow detection relies on length of the sequence skip leading zeros
        while (*s == '0') s++;

        const char_t* start = s;

        for (;;) {
            if (static_cast<unsigned>(*s - '0') < 10)
                result = result * 10 + (*s - '0');
            else
                break;

            s++;
        }

        size_t digits = static_cast<size_t>(s - start);

        PUGI__STATIC_ASSERT(sizeof(U) == 8 || sizeof(U) == 4 || sizeof(U) == 2);

        const size_t max_digits10 = sizeof(U) == 8 ? 20 : sizeof(U) == 4 ? 10 : 5;
        const char_t max_lead     = sizeof(U) == 8 ? '1' : sizeof(U) == 4 ? '4' : '6';
        const size_t high_bit     = sizeof(U) * 8 - 1;

        overflow = digits >= max_digits10 && !(digits == max_digits10 && (*start < max_lead || (*start == max_lead && result >> high_bit)));
    }

    if (negative) {
        // Workaround for crayc++ CC-3059: Expected no overflow in routine.
#    ifdef _CRAYC
        return (overflow || result > ~minv + 1) ? minv : ~result + 1;
#    else
        return (overflow || result > 0 - minv) ? minv : 0 - result;
#    endif
    }
    else
        return (overflow || result > maxv) ? maxv : result;
}

PUGI__FN int get_value_int(const char_t* value)
{
    return string_to_integer<unsigned int>(value, static_cast<unsigned int>(INT_MIN), INT_MAX);
}

PUGI__FN unsigned int get_value_uint(const char_t* value)
{
    return string_to_integer<unsigned int>(value, 0, UINT_MAX);
}

PUGI__FN double get_value_double(const char_t* value)
{
#    ifdef PUGIXML_WCHAR_MODE
    return wcstod(value, 0);
#    else
    return strtod(value, 0);
#    endif
}

PUGI__FN float get_value_float(const char_t* value)
{
#    ifdef PUGIXML_WCHAR_MODE
    return static_cast<float>(wcstod(value, 0));
#    else
    return static_cast<float>(strtod(value, 0));
#    endif
}

PUGI__FN bool get_value_bool(const char_t* value)
{
    // only look at first char
    char_t first = *value;

    // 1*, t* (true), T* (True), y* (yes), Y* (YES)
    return (first == '1' || first == 't' || first == 'T' || first == 'y' || first == 'Y');
}

#    ifdef PUGIXML_HAS_LONG_LONG
PUGI__FN long long get_value_llong(const char_t* value)
{
    return string_to_integer<unsigned long long>(value, static_cast<unsigned long long>(LLONG_MIN), LLONG_MAX);
}

PUGI__FN unsigned long long get_value_ullong(const char_t* value)
{
    return string_to_integer<unsigned long long>(value, 0, ULLONG_MAX);
}
#    endif

template<typename U>
PUGI__FN PUGI__UNSIGNED_OVERFLOW char_t* integer_to_string(char_t* begin, char_t* end, U value, bool negative)
{
    char_t* result = end - 1;
    U       rest   = negative ? 0 - value : value;

    do {
        *result-- = static_cast<char_t>('0' + (rest % 10));
        rest /= 10;
    }
    while (rest);

    assert(result >= begin);
    (void)begin;

    *result = '-';

    return result + !negative;
}

// set value with conversion functions
template<typename String, typename Header>
PUGI__FN bool set_value_ascii(String& dest, Header& header, uintptr_t header_mask, char* buf)
{
#    ifdef PUGIXML_WCHAR_MODE
    char_t wbuf[128];
    assert(strlen(buf) < sizeof(wbuf) / sizeof(wbuf[0]));

    size_t offset = 0;
    for (; buf[offset]; ++offset) wbuf[offset] = buf[offset];

    return strcpy_insitu(dest, header, header_mask, wbuf, offset);
#    else
    return strcpy_insitu(dest, header, header_mask, buf, strlen(buf));
#    endif
}

template<typename U, typename String, typename Header>
PUGI__FN bool set_value_integer(String& dest, Header& header, uintptr_t header_mask, U value, bool negative)
{
    char_t  buf[64];
    char_t* end   = buf + sizeof(buf) / sizeof(buf[0]);
    char_t* begin = integer_to_string(buf, end, value, negative);

    return strcpy_insitu(dest, header, header_mask, begin, end - begin);
}

template<typename String, typename Header>
PUGI__FN bool set_value_convert(String& dest, Header& header, uintptr_t header_mask, float value)
{
    char buf[128];
    PUGI__SNPRINTF(buf, "%.9g", double(value));

    return set_value_ascii(dest, header, header_mask, buf);
}

template<typename String, typename Header>
PUGI__FN bool set_value_convert(String& dest, Header& header, uintptr_t header_mask, double value)
{
    char buf[128];
    PUGI__SNPRINTF(buf, "%.17g", value);

    return set_value_ascii(dest, header, header_mask, buf);
}

template<typename String, typename Header>
PUGI__FN bool set_value_bool(String& dest, Header& header, uintptr_t header_mask, bool value)
{
    return strcpy_insitu(dest, header, header_mask, value ? PUGIXML_TEXT("true") : PUGIXML_TEXT("false"), value ? 4 : 5);
}

PUGI__FN xml_parse_result load_buffer_impl(xml_document_struct* doc,
                                           xml_node_struct*     root,
                                           void*                contents,
                                           size_t               size,
                                           unsigned int         options,
                                           xml_encoding         encoding,
                                           bool                 is_mutable,
                                           bool                 own,
                                           char_t**             out_buffer)
{
    // check input buffer
    if (!contents && size) return make_parse_result(status_io_error);

    // get actual encoding
    xml_encoding buffer_encoding = impl::get_buffer_encoding(encoding, contents, size);

    // get private buffer
    char_t* buffer = 0;
    size_t  length = 0;

    // coverity[var_deref_model]
    if (!impl::convert_buffer(buffer, length, buffer_encoding, contents, size, is_mutable))
        return impl::make_parse_result(status_out_of_memory);

    // delete original buffer if we performed a conversion
    if (own && buffer != contents && contents) impl::xml_memory::deallocate(contents);

    // grab onto buffer if it's our buffer, user is responsible for deallocating contents himself
    if (own || buffer != contents) *out_buffer = buffer;

    // store buffer for offset_debug
    doc->buffer = buffer;

    // parse
    xml_parse_result res = impl::xml_parser::parse(buffer, length, doc, root, options);

    // remember encoding
    res.encoding = buffer_encoding;

    return res;
}

// we need to get length of entire file to load it in memory; the only (relatively) sane way to do it is via seek/tell trick
PUGI__FN xml_parse_status get_file_size(FILE* file, size_t& out_result)
{
#    if defined(PUGI__MSVC_CRT_VERSION) && PUGI__MSVC_CRT_VERSION >= 1400 && !defined(_WIN32_WCE)
    // there are 64-bit versions of fseek/ftell, let's use them
    typedef __int64 length_type;

    _fseeki64(file, 0, SEEK_END);
    length_type length = _ftelli64(file);
    _fseeki64(file, 0, SEEK_SET);
#    elif defined(__MINGW32__) && !defined(__NO_MINGW_LFS) && (!defined(__STRICT_ANSI__) || defined(__MINGW64_VERSION_MAJOR))
    // there are 64-bit versions of fseek/ftell, let's use them
    typedef off64_t length_type;

    fseeko64(file, 0, SEEK_END);
    length_type length = ftello64(file);
    fseeko64(file, 0, SEEK_SET);
#    else
    // if this is a 32-bit OS, long is enough; if this is a unix system, long is 64-bit, which is enough; otherwise we can't do anything
    // anyway.
    typedef long length_type;

    fseek(file, 0, SEEK_END);
    length_type length = ftell(file);
    fseek(file, 0, SEEK_SET);
#    endif

    // check for I/O errors
    if (length < 0) return status_io_error;

    // check for overflow
    size_t result = static_cast<size_t>(length);

    if (static_cast<length_type>(result) != length) return status_out_of_memory;

    // finalize
    out_result = result;

    return status_ok;
}

// This function assumes that buffer has extra sizeof(char_t) writable bytes after size
PUGI__FN size_t zero_terminate_buffer(void* buffer, size_t size, xml_encoding encoding)
{
    // We only need to zero-terminate if encoding conversion does not do it for us
#    ifdef PUGIXML_WCHAR_MODE
    xml_encoding wchar_encoding = get_wchar_encoding();

    if (encoding == wchar_encoding || need_endian_swap_utf(encoding, wchar_encoding)) {
        size_t length = size / sizeof(char_t);

        static_cast<char_t*>(buffer)[length] = 0;
        return (length + 1) * sizeof(char_t);
    }
#    else
    if (encoding == encoding_utf8) {
        static_cast<char*>(buffer)[size] = 0;
        return size + 1;
    }
#    endif

    return size;
}

PUGI__FN xml_parse_result
    load_file_impl(xml_document_struct* doc, FILE* file, unsigned int options, xml_encoding encoding, char_t** out_buffer)
{
    if (!file) return make_parse_result(status_file_not_found);

    // get file size (can result in I/O errors)
    size_t           size        = 0;
    xml_parse_status size_status = get_file_size(file, size);
    if (size_status != status_ok) return make_parse_result(size_status);

    size_t max_suffix_size = sizeof(char_t);

    // allocate buffer for the whole file
    char* contents = static_cast<char*>(xml_memory::allocate(size + max_suffix_size));
    if (!contents) return make_parse_result(status_out_of_memory);

    // read file in memory
    size_t read_size = fread(contents, 1, size, file);

    if (read_size != size) {
        xml_memory::deallocate(contents);
        return make_parse_result(status_io_error);
    }

    xml_encoding real_encoding = get_buffer_encoding(encoding, contents, size);

    return load_buffer_impl(doc,
                            doc,
                            contents,
                            zero_terminate_buffer(contents, size, real_encoding),
                            options,
                            real_encoding,
                            true,
                            true,
                            out_buffer);
}

PUGI__FN void close_file(FILE* file)
{
    fclose(file);
}

#    ifndef PUGIXML_NO_STL
template<typename T>
struct xml_stream_chunk
{
    static xml_stream_chunk* create()
    {
        void* memory = xml_memory::allocate(sizeof(xml_stream_chunk));
        if (!memory) return 0;

        return new (memory) xml_stream_chunk();
    }

    static void destroy(xml_stream_chunk* chunk)
    {
        // free chunk chain
        while (chunk) {
            xml_stream_chunk* next_ = chunk->next;

            xml_memory::deallocate(chunk);

            chunk = next_;
        }
    }

    xml_stream_chunk() : next(0), size(0) {}

    xml_stream_chunk* next;
    size_t            size;

    T data[xml_memory_page_size / sizeof(T)];
};

template<typename T>
PUGI__FN xml_parse_status load_stream_data_noseek(std::basic_istream<T>& stream, void** out_buffer, size_t* out_size)
{
    auto_deleter<xml_stream_chunk<T> > chunks(0, xml_stream_chunk<T>::destroy);

    // read file to a chunk list
    size_t               total = 0;
    xml_stream_chunk<T>* last  = 0;

    while (!stream.eof()) {
        // allocate new chunk
        xml_stream_chunk<T>* chunk = xml_stream_chunk<T>::create();
        if (!chunk) return status_out_of_memory;

        // append chunk to list
        if (last)
            last = last->next = chunk;
        else
            chunks.data = last = chunk;

        // read data to chunk
        stream.read(chunk->data, static_cast<std::streamsize>(sizeof(chunk->data) / sizeof(T)));
        chunk->size = static_cast<size_t>(stream.gcount()) * sizeof(T);

        // read may set failbit | eofbit in case gcount() is less than read length, so check for other I/O errors
        if (stream.bad() || (!stream.eof() && stream.fail())) return status_io_error;

        // guard against huge files (chunk size is small enough to make this overflow check work)
        if (total + chunk->size < total) return status_out_of_memory;
        total += chunk->size;
    }

    size_t max_suffix_size = sizeof(char_t);

    // copy chunk list to a contiguous buffer
    char* buffer = static_cast<char*>(xml_memory::allocate(total + max_suffix_size));
    if (!buffer) return status_out_of_memory;

    char* write = buffer;

    for (xml_stream_chunk<T>* chunk = chunks.data; chunk; chunk = chunk->next) {
        assert(write + chunk->size <= buffer + total);
        memcpy(write, chunk->data, chunk->size);
        write += chunk->size;
    }

    assert(write == buffer + total);

    // return buffer
    *out_buffer = buffer;
    *out_size   = total;

    return status_ok;
}

template<typename T>
PUGI__FN xml_parse_status load_stream_data_seek(std::basic_istream<T>& stream, void** out_buffer, size_t* out_size)
{
    // get length of remaining data in stream
    typename std::basic_istream<T>::pos_type pos = stream.tellg();
    stream.seekg(0, std::ios::end);
    std::streamoff length = stream.tellg() - pos;
    stream.seekg(pos);

    if (stream.fail() || pos < 0) return status_io_error;

    // guard against huge files
    size_t read_length = static_cast<size_t>(length);

    if (static_cast<std::streamsize>(read_length) != length || length < 0) return status_out_of_memory;

    size_t max_suffix_size = sizeof(char_t);

    // read stream data into memory (guard against stream exceptions with buffer holder)
    auto_deleter<void> buffer(xml_memory::allocate(read_length * sizeof(T) + max_suffix_size), xml_memory::deallocate);
    if (!buffer.data) return status_out_of_memory;

    stream.read(static_cast<T*>(buffer.data), static_cast<std::streamsize>(read_length));

    // read may set failbit | eofbit in case gcount() is less than read_length (i.e. line ending conversion), so check for other I/O errors
    if (stream.bad() || (!stream.eof() && stream.fail())) return status_io_error;

    // return buffer
    size_t actual_length = static_cast<size_t>(stream.gcount());
    assert(actual_length <= read_length);

    *out_buffer = buffer.release();
    *out_size   = actual_length * sizeof(T);

    return status_ok;
}

template<typename T>
PUGI__FN xml_parse_result load_stream_impl(xml_document_struct*   doc,
                                           std::basic_istream<T>& stream,
                                           unsigned int           options,
                                           xml_encoding           encoding,
                                           char_t**               out_buffer)
{
    void*            buffer = 0;
    size_t           size   = 0;
    xml_parse_status status = status_ok;

    // if stream has an error bit set, bail out (otherwise tellg() can fail and we'll clear error bits)
    if (stream.fail()) return make_parse_result(status_io_error);

    // load stream to memory (using seek-based implementation if possible, since it's faster and takes less memory)
    if (stream.tellg() < 0) {
        stream.clear();    // clear error flags that could be set by a failing tellg
        status = load_stream_data_noseek(stream, &buffer, &size);
    }
    else
        status = load_stream_data_seek(stream, &buffer, &size);

    if (status != status_ok) return make_parse_result(status);

    xml_encoding real_encoding = get_buffer_encoding(encoding, buffer, size);

    return load_buffer_impl(doc,
                            doc,
                            buffer,
                            zero_terminate_buffer(buffer, size, real_encoding),
                            options,
                            real_encoding,
                            true,
                            true,
                            out_buffer);
}
#    endif

#    if defined(PUGI__MSVC_CRT_VERSION) || defined(__BORLANDC__) || \
        (defined(__MINGW32__) && (!defined(__STRICT_ANSI__) || defined(__MINGW64_VERSION_MAJOR)))
PUGI__FN FILE* open_file_wide(const wchar_t* path, const wchar_t* mode)
{
    return _wfopen(path, mode);
}
#    else
PUGI__FN char* convert_path_heap(const wchar_t* str)
{
    assert(str);

    // first pass: get length in utf8 characters
    size_t length = strlength_wide(str);
    size_t size = as_utf8_begin(str, length);

    // allocate resulting string
    char* result = static_cast<char*>(xml_memory::allocate(size + 1));
    if (!result) return 0;

    // second pass: convert to utf8
    as_utf8_end(result, size, str, length);

    // zero-terminate
    result[size] = 0;

    return result;
}

PUGI__FN FILE* open_file_wide(const wchar_t* path, const wchar_t* mode)
{
    // there is no standard function to open wide paths, so our best bet is to try utf8 path
    char* path_utf8 = convert_path_heap(path);
    if (!path_utf8) return 0;

    // convert mode to ASCII (we mirror _wfopen interface)
    char mode_ascii[4] = { 0 };
    for (size_t i = 0; mode[i]; ++i) mode_ascii[i] = static_cast<char>(mode[i]);

    // try to open the utf8 path
    FILE* result = fopen(path_utf8, mode_ascii);

    // free dummy buffer
    xml_memory::deallocate(path_utf8);

    return result;
}
#    endif

PUGI__FN bool save_file_impl(const xml_document& doc, FILE* file, const char_t* indent, unsigned int flags, xml_encoding encoding)
{
    if (!file) return false;

    xml_writer_file writer(file);
    doc.save(writer, indent, flags, encoding);

    return ferror(file) == 0;
}

struct name_null_sentry
{
    xml_node_struct* node;
    char_t*          name;

    name_null_sentry(xml_node_struct* node_) : node(node_), name(node_->name)
    {
        node->name = 0;
    }

    ~name_null_sentry()
    {
        node->name = name;
    }
};
PUGI__NS_END

namespace pugi
{
    PUGI__FN xml_writer_file::xml_writer_file(void* file_) : file(file_) {}

    PUGI__FN void xml_writer_file::write(const void* data, size_t size)
    {
        size_t result = fwrite(data, 1, size, static_cast<FILE*>(file));
        (void)!result;    // unfortunately we can't do proper error handling here
    }

#    ifndef PUGIXML_NO_STL
    PUGI__FN xml_writer_stream::xml_writer_stream(std::basic_ostream<char, std::char_traits<char> >& stream)
        : narrow_stream(&stream),
          wide_stream(0)
    {}

    PUGI__FN xml_writer_stream::xml_writer_stream(std::basic_ostream<wchar_t, std::char_traits<wchar_t> >& stream)
        : narrow_stream(0),
          wide_stream(&stream)
    {}

    PUGI__FN void xml_writer_stream::write(const void* data, size_t size)
    {
        if (narrow_stream) {
            assert(!wide_stream);
            narrow_stream->write(reinterpret_cast<const char*>(data), static_cast<std::streamsize>(size));
        }
        else {
            assert(wide_stream);
            assert(size % sizeof(wchar_t) == 0);

            wide_stream->write(reinterpret_cast<const wchar_t*>(data), static_cast<std::streamsize>(size / sizeof(wchar_t)));
        }
    }
#    endif

    PUGI__FN xml_tree_walker::xml_tree_walker() : _depth(0) {}

    PUGI__FN xml_tree_walker::~xml_tree_walker() {}

    PUGI__FN int xml_tree_walker::depth() const
    {
        return _depth;
    }

    PUGI__FN bool xml_tree_walker::begin(xml_node&)
    {
        return true;
    }

    PUGI__FN bool xml_tree_walker::end(xml_node&)
    {
        return true;
    }

    PUGI__FN xml_attribute::xml_attribute() : _attr(0) {}

    PUGI__FN xml_attribute::xml_attribute(xml_attribute_struct* attr) : _attr(attr) {}

    PUGI__FN static void unspecified_bool_xml_attribute(xml_attribute***) {}

    PUGI__FN xml_attribute::operator xml_attribute::unspecified_bool_type() const
    {
        return _attr ? unspecified_bool_xml_attribute : 0;
    }

    PUGI__FN bool xml_attribute::operator!() const
    {
        return !_attr;
    }

    PUGI__FN bool xml_attribute::operator==(const xml_attribute& r) const
    {
        return (_attr == r._attr);
    }

    PUGI__FN bool xml_attribute::operator!=(const xml_attribute& r) const
    {
        return (_attr != r._attr);
    }

    PUGI__FN bool xml_attribute::operator<(const xml_attribute& r) const
    {
        return (_attr < r._attr);
    }

    PUGI__FN bool xml_attribute::operator>(const xml_attribute& r) const
    {
        return (_attr > r._attr);
    }

    PUGI__FN bool xml_attribute::operator<=(const xml_attribute& r) const
    {
        return (_attr <= r._attr);
    }

    PUGI__FN bool xml_attribute::operator>=(const xml_attribute& r) const
    {
        return (_attr >= r._attr);
    }

    PUGI__FN xml_attribute xml_attribute::next_attribute() const
    {
        return _attr ? xml_attribute(_attr->next_attribute) : xml_attribute();
    }

    PUGI__FN xml_attribute xml_attribute::previous_attribute() const
    {
        return _attr && _attr->prev_attribute_c->next_attribute ? xml_attribute(_attr->prev_attribute_c) : xml_attribute();
    }

    PUGI__FN const char_t* xml_attribute::as_string(const char_t* def) const
    {
        return (_attr && _attr->value) ? _attr->value + 0 : def;
    }

    PUGI__FN int xml_attribute::as_int(int def) const
    {
        return (_attr && _attr->value) ? impl::get_value_int(_attr->value) : def;
    }

    PUGI__FN unsigned int xml_attribute::as_uint(unsigned int def) const
    {
        return (_attr && _attr->value) ? impl::get_value_uint(_attr->value) : def;
    }

    PUGI__FN double xml_attribute::as_double(double def) const
    {
        return (_attr && _attr->value) ? impl::get_value_double(_attr->value) : def;
    }

    PUGI__FN float xml_attribute::as_float(float def) const
    {
        return (_attr && _attr->value) ? impl::get_value_float(_attr->value) : def;
    }

    PUGI__FN bool xml_attribute::as_bool(bool def) const
    {
        return (_attr && _attr->value) ? impl::get_value_bool(_attr->value) : def;
    }

#    ifdef PUGIXML_HAS_LONG_LONG
    PUGI__FN long long xml_attribute::as_llong(long long def) const
    {
        return (_attr && _attr->value) ? impl::get_value_llong(_attr->value) : def;
    }

    PUGI__FN unsigned long long xml_attribute::as_ullong(unsigned long long def) const
    {
        return (_attr && _attr->value) ? impl::get_value_ullong(_attr->value) : def;
    }
#    endif

    PUGI__FN bool xml_attribute::empty() const
    {
        return !_attr;
    }

    PUGI__FN const char_t* xml_attribute::name() const
    {
        return (_attr && _attr->name) ? _attr->name + 0 : PUGIXML_TEXT("");
    }

    PUGI__FN const char_t* xml_attribute::value() const
    {
        return (_attr && _attr->value) ? _attr->value + 0 : PUGIXML_TEXT("");
    }

    PUGI__FN size_t xml_attribute::hash_value() const
    {
        return static_cast<size_t>(reinterpret_cast<uintptr_t>(_attr) / sizeof(xml_attribute_struct));
    }

    PUGI__FN xml_attribute_struct* xml_attribute::internal_object() const
    {
        return _attr;
    }

    PUGI__FN xml_attribute& xml_attribute::operator=(const char_t* rhs)
    {
        set_value(rhs);
        return *this;
    }

    PUGI__FN xml_attribute& xml_attribute::operator=(int rhs)
    {
        set_value(rhs);
        return *this;
    }

    PUGI__FN xml_attribute& xml_attribute::operator=(unsigned int rhs)
    {
        set_value(rhs);
        return *this;
    }

    PUGI__FN xml_attribute& xml_attribute::operator=(long rhs)
    {
        set_value(rhs);
        return *this;
    }

    PUGI__FN xml_attribute& xml_attribute::operator=(unsigned long rhs)
    {
        set_value(rhs);
        return *this;
    }

    PUGI__FN xml_attribute& xml_attribute::operator=(double rhs)
    {
        set_value(rhs);
        return *this;
    }

    PUGI__FN xml_attribute& xml_attribute::operator=(float rhs)
    {
        set_value(rhs);
        return *this;
    }

    PUGI__FN xml_attribute& xml_attribute::operator=(bool rhs)
    {
        set_value(rhs);
        return *this;
    }

#    ifdef PUGIXML_HAS_LONG_LONG
    PUGI__FN xml_attribute& xml_attribute::operator=(long long rhs)
    {
        set_value(rhs);
        return *this;
    }

    PUGI__FN xml_attribute& xml_attribute::operator=(unsigned long long rhs)
    {
        set_value(rhs);
        return *this;
    }
#    endif

    PUGI__FN bool xml_attribute::set_name(const char_t* rhs)
    {
        if (!_attr) return false;

        return impl::strcpy_insitu(_attr->name, _attr->header, impl::xml_memory_page_name_allocated_mask, rhs, impl::strlength(rhs));
    }

    PUGI__FN bool xml_attribute::set_value(const char_t* rhs)
    {
        if (!_attr) return false;

        return impl::strcpy_insitu(_attr->value, _attr->header, impl::xml_memory_page_value_allocated_mask, rhs, impl::strlength(rhs));
    }

    PUGI__FN bool xml_attribute::set_value(int rhs)
    {
        if (!_attr) return false;

        return impl::set_value_integer<unsigned int>(_attr->value, _attr->header, impl::xml_memory_page_value_allocated_mask, rhs, rhs < 0);
    }

    PUGI__FN bool xml_attribute::set_value(unsigned int rhs)
    {
        if (!_attr) return false;

        return impl::set_value_integer<unsigned int>(_attr->value, _attr->header, impl::xml_memory_page_value_allocated_mask, rhs, false);
    }

    PUGI__FN bool xml_attribute::set_value(long rhs)
    {
        if (!_attr) return false;

        return impl::set_value_integer<unsigned long>(_attr->value,
                                                      _attr->header,
                                                      impl::xml_memory_page_value_allocated_mask,
                                                      rhs,
                                                      rhs < 0);
    }

    PUGI__FN bool xml_attribute::set_value(unsigned long rhs)
    {
        if (!_attr) return false;

        return impl::set_value_integer<unsigned long>(_attr->value, _attr->header, impl::xml_memory_page_value_allocated_mask, rhs, false);
    }

    PUGI__FN bool xml_attribute::set_value(double rhs)
    {
        if (!_attr) return false;

        return impl::set_value_convert(_attr->value, _attr->header, impl::xml_memory_page_value_allocated_mask, rhs);
    }

    PUGI__FN bool xml_attribute::set_value(float rhs)
    {
        if (!_attr) return false;

        return impl::set_value_convert(_attr->value, _attr->header, impl::xml_memory_page_value_allocated_mask, rhs);
    }

    PUGI__FN bool xml_attribute::set_value(bool rhs)
    {
        if (!_attr) return false;

        return impl::set_value_bool(_attr->value, _attr->header, impl::xml_memory_page_value_allocated_mask, rhs);
    }

#    ifdef PUGIXML_HAS_LONG_LONG
    PUGI__FN bool xml_attribute::set_value(long long rhs)
    {
        if (!_attr) return false;

        return impl::set_value_integer<unsigned long long>(_attr->value,
                                                           _attr->header,
                                                           impl::xml_memory_page_value_allocated_mask,
                                                           rhs,
                                                           rhs < 0);
    }

    PUGI__FN bool xml_attribute::set_value(unsigned long long rhs)
    {
        if (!_attr) return false;

        return impl::set_value_integer<unsigned long long>(_attr->value,
                                                           _attr->header,
                                                           impl::xml_memory_page_value_allocated_mask,
                                                           rhs,
                                                           false);
    }
#    endif

#    ifdef __BORLANDC__
    PUGI__FN bool operator&&(const xml_attribute& lhs, bool rhs)
    {
        return (bool)lhs && rhs;
    }

    PUGI__FN bool operator||(const xml_attribute& lhs, bool rhs)
    {
        return (bool)lhs || rhs;
    }
#    endif

    PUGI__FN xml_node::xml_node() : _root(0) {}

    PUGI__FN xml_node::xml_node(xml_node_struct* p) : _root(p) {}

    PUGI__FN static void unspecified_bool_xml_node(xml_node***) {}

    PUGI__FN xml_node::operator xml_node::unspecified_bool_type() const
    {
        return _root ? unspecified_bool_xml_node : 0;
    }

    PUGI__FN bool xml_node::operator!() const
    {
        return !_root;
    }

    PUGI__FN xml_node::iterator xml_node::begin() const
    {
        return iterator(_root ? _root->first_child + 0 : 0, _root);
    }

    PUGI__FN xml_node::iterator xml_node::end() const
    {
        return iterator(0, _root);
    }

    PUGI__FN xml_node::attribute_iterator xml_node::attributes_begin() const
    {
        return attribute_iterator(_root ? _root->first_attribute + 0 : 0, _root);
    }

    PUGI__FN xml_node::attribute_iterator xml_node::attributes_end() const
    {
        return attribute_iterator(0, _root);
    }

    PUGI__FN xml_object_range<xml_node_iterator> xml_node::children() const
    {
        return xml_object_range<xml_node_iterator>(begin(), end());
    }

    PUGI__FN xml_object_range<xml_named_node_iterator> xml_node::children(const char_t* name_) const
    {
        return xml_object_range<xml_named_node_iterator>(xml_named_node_iterator(child(name_)._root, _root, name_),
                                                         xml_named_node_iterator(0, _root, name_));
    }

    PUGI__FN xml_object_range<xml_attribute_iterator> xml_node::attributes() const
    {
        return xml_object_range<xml_attribute_iterator>(attributes_begin(), attributes_end());
    }

    PUGI__FN bool xml_node::operator==(const xml_node& r) const
    {
        return (_root == r._root);
    }

    PUGI__FN bool xml_node::operator!=(const xml_node& r) const
    {
        return (_root != r._root);
    }

    PUGI__FN bool xml_node::operator<(const xml_node& r) const
    {
        return (_root < r._root);
    }

    PUGI__FN bool xml_node::operator>(const xml_node& r) const
    {
        return (_root > r._root);
    }

    PUGI__FN bool xml_node::operator<=(const xml_node& r) const
    {
        return (_root <= r._root);
    }

    PUGI__FN bool xml_node::operator>=(const xml_node& r) const
    {
        return (_root >= r._root);
    }

    PUGI__FN bool xml_node::empty() const
    {
        return !_root;
    }

    PUGI__FN const char_t* xml_node::name() const
    {
        return (_root && _root->name) ? _root->name + 0 : PUGIXML_TEXT("");
    }

    PUGI__FN xml_node_type xml_node::type() const
    {
        return _root ? PUGI__NODETYPE(_root) : node_null;
    }

    PUGI__FN const char_t* xml_node::value() const
    {
        return (_root && _root->value) ? _root->value + 0 : PUGIXML_TEXT("");
    }

    PUGI__FN xml_node xml_node::child(const char_t* name_) const
    {
        if (!_root) return xml_node();

        for (xml_node_struct* i = _root->first_child; i; i = i->next_sibling)
            if (i->name && impl::strequal(name_, i->name)) return xml_node(i);

        return xml_node();
    }

    PUGI__FN xml_attribute xml_node::attribute(const char_t* name_) const
    {
        if (!_root) return xml_attribute();

        for (xml_attribute_struct* i = _root->first_attribute; i; i = i->next_attribute)
            if (i->name && impl::strequal(name_, i->name)) return xml_attribute(i);

        return xml_attribute();
    }

    PUGI__FN xml_node xml_node::next_sibling(const char_t* name_) const
    {
        if (!_root) return xml_node();

        for (xml_node_struct* i = _root->next_sibling; i; i = i->next_sibling)
            if (i->name && impl::strequal(name_, i->name)) return xml_node(i);

        return xml_node();
    }

    PUGI__FN xml_node xml_node::next_sibling() const
    {
        return _root ? xml_node(_root->next_sibling) : xml_node();
    }

    PUGI__FN xml_node xml_node::previous_sibling(const char_t* name_) const
    {
        if (!_root) return xml_node();

        for (xml_node_struct* i = _root->prev_sibling_c; i->next_sibling; i = i->prev_sibling_c)
            if (i->name && impl::strequal(name_, i->name)) return xml_node(i);

        return xml_node();
    }

    PUGI__FN xml_attribute xml_node::attribute(const char_t* name_, xml_attribute& hint_) const
    {
        xml_attribute_struct* hint = hint_._attr;

        // if hint is not an attribute of node, behavior is not defined
        assert(!hint || (_root && impl::is_attribute_of(hint, _root)));

        if (!_root) return xml_attribute();

        // optimistically search from hint up until the end
        for (xml_attribute_struct* i = hint; i; i = i->next_attribute)
            if (i->name && impl::strequal(name_, i->name)) {
                // update hint to maximize efficiency of searching for consecutive attributes
                hint_._attr = i->next_attribute;

                return xml_attribute(i);
            }

        // wrap around and search from the first attribute until the hint
        // 'j' null pointer check is technically redundant, but it prevents a crash in case the assertion above fails
        for (xml_attribute_struct* j = _root->first_attribute; j && j != hint; j = j->next_attribute)
            if (j->name && impl::strequal(name_, j->name)) {
                // update hint to maximize efficiency of searching for consecutive attributes
                hint_._attr = j->next_attribute;

                return xml_attribute(j);
            }

        return xml_attribute();
    }

    PUGI__FN xml_node xml_node::previous_sibling() const
    {
        if (!_root) return xml_node();

        if (_root->prev_sibling_c->next_sibling)
            return xml_node(_root->prev_sibling_c);
        else
            return xml_node();
    }

    PUGI__FN xml_node xml_node::parent() const
    {
        return _root ? xml_node(_root->parent) : xml_node();
    }

    PUGI__FN xml_node xml_node::root() const
    {
        return _root ? xml_node(&impl::get_document(_root)) : xml_node();
    }

    PUGI__FN xml_text xml_node::text() const
    {
        return xml_text(_root);
    }

    PUGI__FN const char_t* xml_node::child_value() const
    {
        if (!_root) return PUGIXML_TEXT("");

        // element nodes can have value if parse_embed_pcdata was used
        if (PUGI__NODETYPE(_root) == node_element && _root->value) return _root->value;

        for (xml_node_struct* i = _root->first_child; i; i = i->next_sibling)
            if (impl::is_text_node(i) && i->value) return i->value;

        return PUGIXML_TEXT("");
    }

    PUGI__FN const char_t* xml_node::child_value(const char_t* name_) const
    {
        return child(name_).child_value();
    }

    PUGI__FN xml_attribute xml_node::first_attribute() const
    {
        return _root ? xml_attribute(_root->first_attribute) : xml_attribute();
    }

    PUGI__FN xml_attribute xml_node::last_attribute() const
    {
        return _root && _root->first_attribute ? xml_attribute(_root->first_attribute->prev_attribute_c) : xml_attribute();
    }

    PUGI__FN xml_node xml_node::first_child() const
    {
        return _root ? xml_node(_root->first_child) : xml_node();
    }

    PUGI__FN xml_node xml_node::last_child() const
    {
        return _root && _root->first_child ? xml_node(_root->first_child->prev_sibling_c) : xml_node();
    }

    PUGI__FN bool xml_node::set_name(const char_t* rhs)
    {
        xml_node_type type_ = _root ? PUGI__NODETYPE(_root) : node_null;

        if (type_ != node_element && type_ != node_pi && type_ != node_declaration) return false;

        return impl::strcpy_insitu(_root->name, _root->header, impl::xml_memory_page_name_allocated_mask, rhs, impl::strlength(rhs));
    }

    PUGI__FN bool xml_node::set_value(const char_t* rhs)
    {
        xml_node_type type_ = _root ? PUGI__NODETYPE(_root) : node_null;

        if (type_ != node_pcdata && type_ != node_cdata && type_ != node_comment && type_ != node_pi && type_ != node_doctype) return false;

        return impl::strcpy_insitu(_root->value, _root->header, impl::xml_memory_page_value_allocated_mask, rhs, impl::strlength(rhs));
    }

    PUGI__FN xml_attribute xml_node::append_attribute(const char_t* name_)
    {
        if (!impl::allow_insert_attribute(type())) return xml_attribute();

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return xml_attribute();

        xml_attribute a(impl::allocate_attribute(alloc));
        if (!a) return xml_attribute();

        impl::append_attribute(a._attr, _root);

        a.set_name(name_);

        return a;
    }

    PUGI__FN xml_attribute xml_node::prepend_attribute(const char_t* name_)
    {
        if (!impl::allow_insert_attribute(type())) return xml_attribute();

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return xml_attribute();

        xml_attribute a(impl::allocate_attribute(alloc));
        if (!a) return xml_attribute();

        impl::prepend_attribute(a._attr, _root);

        a.set_name(name_);

        return a;
    }

    PUGI__FN xml_attribute xml_node::insert_attribute_after(const char_t* name_, const xml_attribute& attr)
    {
        if (!impl::allow_insert_attribute(type())) return xml_attribute();
        if (!attr || !impl::is_attribute_of(attr._attr, _root)) return xml_attribute();

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return xml_attribute();

        xml_attribute a(impl::allocate_attribute(alloc));
        if (!a) return xml_attribute();

        impl::insert_attribute_after(a._attr, attr._attr, _root);

        a.set_name(name_);

        return a;
    }

    PUGI__FN xml_attribute xml_node::insert_attribute_before(const char_t* name_, const xml_attribute& attr)
    {
        if (!impl::allow_insert_attribute(type())) return xml_attribute();
        if (!attr || !impl::is_attribute_of(attr._attr, _root)) return xml_attribute();

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return xml_attribute();

        xml_attribute a(impl::allocate_attribute(alloc));
        if (!a) return xml_attribute();

        impl::insert_attribute_before(a._attr, attr._attr, _root);

        a.set_name(name_);

        return a;
    }

    PUGI__FN xml_attribute xml_node::append_copy(const xml_attribute& proto)
    {
        if (!proto) return xml_attribute();
        if (!impl::allow_insert_attribute(type())) return xml_attribute();

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return xml_attribute();

        xml_attribute a(impl::allocate_attribute(alloc));
        if (!a) return xml_attribute();

        impl::append_attribute(a._attr, _root);
        impl::node_copy_attribute(a._attr, proto._attr);

        return a;
    }

    PUGI__FN xml_attribute xml_node::prepend_copy(const xml_attribute& proto)
    {
        if (!proto) return xml_attribute();
        if (!impl::allow_insert_attribute(type())) return xml_attribute();

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return xml_attribute();

        xml_attribute a(impl::allocate_attribute(alloc));
        if (!a) return xml_attribute();

        impl::prepend_attribute(a._attr, _root);
        impl::node_copy_attribute(a._attr, proto._attr);

        return a;
    }

    PUGI__FN xml_attribute xml_node::insert_copy_after(const xml_attribute& proto, const xml_attribute& attr)
    {
        if (!proto) return xml_attribute();
        if (!impl::allow_insert_attribute(type())) return xml_attribute();
        if (!attr || !impl::is_attribute_of(attr._attr, _root)) return xml_attribute();

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return xml_attribute();

        xml_attribute a(impl::allocate_attribute(alloc));
        if (!a) return xml_attribute();

        impl::insert_attribute_after(a._attr, attr._attr, _root);
        impl::node_copy_attribute(a._attr, proto._attr);

        return a;
    }

    PUGI__FN xml_attribute xml_node::insert_copy_before(const xml_attribute& proto, const xml_attribute& attr)
    {
        if (!proto) return xml_attribute();
        if (!impl::allow_insert_attribute(type())) return xml_attribute();
        if (!attr || !impl::is_attribute_of(attr._attr, _root)) return xml_attribute();

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return xml_attribute();

        xml_attribute a(impl::allocate_attribute(alloc));
        if (!a) return xml_attribute();

        impl::insert_attribute_before(a._attr, attr._attr, _root);
        impl::node_copy_attribute(a._attr, proto._attr);

        return a;
    }

    PUGI__FN xml_node xml_node::append_child(xml_node_type type_)
    {
        if (!impl::allow_insert_child(type(), type_)) return xml_node();

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return xml_node();

        xml_node n(impl::allocate_node(alloc, type_));
        if (!n) return xml_node();

        impl::append_node(n._root, _root);

        if (type_ == node_declaration) n.set_name(PUGIXML_TEXT("xml"));

        return n;
    }

    PUGI__FN xml_node xml_node::prepend_child(xml_node_type type_)
    {
        if (!impl::allow_insert_child(type(), type_)) return xml_node();

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return xml_node();

        xml_node n(impl::allocate_node(alloc, type_));
        if (!n) return xml_node();

        impl::prepend_node(n._root, _root);

        if (type_ == node_declaration) n.set_name(PUGIXML_TEXT("xml"));

        return n;
    }

    PUGI__FN xml_node xml_node::insert_child_before(xml_node_type type_, const xml_node& node)
    {
        if (!impl::allow_insert_child(type(), type_)) return xml_node();
        if (!node._root || node._root->parent != _root) return xml_node();

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return xml_node();

        xml_node n(impl::allocate_node(alloc, type_));
        if (!n) return xml_node();

        impl::insert_node_before(n._root, node._root);

        if (type_ == node_declaration) n.set_name(PUGIXML_TEXT("xml"));

        return n;
    }

    PUGI__FN xml_node xml_node::insert_child_after(xml_node_type type_, const xml_node& node)
    {
        if (!impl::allow_insert_child(type(), type_)) return xml_node();
        if (!node._root || node._root->parent != _root) return xml_node();

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return xml_node();

        xml_node n(impl::allocate_node(alloc, type_));
        if (!n) return xml_node();

        impl::insert_node_after(n._root, node._root);

        if (type_ == node_declaration) n.set_name(PUGIXML_TEXT("xml"));

        return n;
    }

    PUGI__FN xml_node xml_node::append_child(const char_t* name_)
    {
        xml_node result = append_child(node_element);

        result.set_name(name_);

        return result;
    }

    PUGI__FN xml_node xml_node::prepend_child(const char_t* name_)
    {
        xml_node result = prepend_child(node_element);

        result.set_name(name_);

        return result;
    }

    PUGI__FN xml_node xml_node::insert_child_after(const char_t* name_, const xml_node& node)
    {
        xml_node result = insert_child_after(node_element, node);

        result.set_name(name_);

        return result;
    }

    PUGI__FN xml_node xml_node::insert_child_before(const char_t* name_, const xml_node& node)
    {
        xml_node result = insert_child_before(node_element, node);

        result.set_name(name_);

        return result;
    }

    PUGI__FN xml_node xml_node::append_copy(const xml_node& proto)
    {
        xml_node_type type_ = proto.type();
        if (!impl::allow_insert_child(type(), type_)) return xml_node();

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return xml_node();

        xml_node n(impl::allocate_node(alloc, type_));
        if (!n) return xml_node();

        impl::append_node(n._root, _root);
        impl::node_copy_tree(n._root, proto._root);

        return n;
    }

    PUGI__FN xml_node xml_node::prepend_copy(const xml_node& proto)
    {
        xml_node_type type_ = proto.type();
        if (!impl::allow_insert_child(type(), type_)) return xml_node();

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return xml_node();

        xml_node n(impl::allocate_node(alloc, type_));
        if (!n) return xml_node();

        impl::prepend_node(n._root, _root);
        impl::node_copy_tree(n._root, proto._root);

        return n;
    }

    PUGI__FN xml_node xml_node::insert_copy_after(const xml_node& proto, const xml_node& node)
    {
        xml_node_type type_ = proto.type();
        if (!impl::allow_insert_child(type(), type_)) return xml_node();
        if (!node._root || node._root->parent != _root) return xml_node();

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return xml_node();

        xml_node n(impl::allocate_node(alloc, type_));
        if (!n) return xml_node();

        impl::insert_node_after(n._root, node._root);
        impl::node_copy_tree(n._root, proto._root);

        return n;
    }

    PUGI__FN xml_node xml_node::insert_copy_before(const xml_node& proto, const xml_node& node)
    {
        xml_node_type type_ = proto.type();
        if (!impl::allow_insert_child(type(), type_)) return xml_node();
        if (!node._root || node._root->parent != _root) return xml_node();

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return xml_node();

        xml_node n(impl::allocate_node(alloc, type_));
        if (!n) return xml_node();

        impl::insert_node_before(n._root, node._root);
        impl::node_copy_tree(n._root, proto._root);

        return n;
    }

    PUGI__FN xml_node xml_node::append_move(const xml_node& moved)
    {
        if (!impl::allow_move(*this, moved)) return xml_node();

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return xml_node();

        // disable document_buffer_order optimization since moving nodes around changes document order without changing buffer pointers
        impl::get_document(_root).header |= impl::xml_memory_page_contents_shared_mask;

        impl::remove_node(moved._root);
        impl::append_node(moved._root, _root);

        return moved;
    }

    PUGI__FN xml_node xml_node::prepend_move(const xml_node& moved)
    {
        if (!impl::allow_move(*this, moved)) return xml_node();

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return xml_node();

        // disable document_buffer_order optimization since moving nodes around changes document order without changing buffer pointers
        impl::get_document(_root).header |= impl::xml_memory_page_contents_shared_mask;

        impl::remove_node(moved._root);
        impl::prepend_node(moved._root, _root);

        return moved;
    }

    PUGI__FN xml_node xml_node::insert_move_after(const xml_node& moved, const xml_node& node)
    {
        if (!impl::allow_move(*this, moved)) return xml_node();
        if (!node._root || node._root->parent != _root) return xml_node();
        if (moved._root == node._root) return xml_node();

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return xml_node();

        // disable document_buffer_order optimization since moving nodes around changes document order without changing buffer pointers
        impl::get_document(_root).header |= impl::xml_memory_page_contents_shared_mask;

        impl::remove_node(moved._root);
        impl::insert_node_after(moved._root, node._root);

        return moved;
    }

    PUGI__FN xml_node xml_node::insert_move_before(const xml_node& moved, const xml_node& node)
    {
        if (!impl::allow_move(*this, moved)) return xml_node();
        if (!node._root || node._root->parent != _root) return xml_node();
        if (moved._root == node._root) return xml_node();

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return xml_node();

        // disable document_buffer_order optimization since moving nodes around changes document order without changing buffer pointers
        impl::get_document(_root).header |= impl::xml_memory_page_contents_shared_mask;

        impl::remove_node(moved._root);
        impl::insert_node_before(moved._root, node._root);

        return moved;
    }

    PUGI__FN bool xml_node::remove_attribute(const char_t* name_)
    {
        return remove_attribute(attribute(name_));
    }

    PUGI__FN bool xml_node::remove_attribute(const xml_attribute& a)
    {
        if (!_root || !a._attr) return false;
        if (!impl::is_attribute_of(a._attr, _root)) return false;

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return false;

        impl::remove_attribute(a._attr, _root);
        impl::destroy_attribute(a._attr, alloc);

        return true;
    }

    PUGI__FN bool xml_node::remove_child(const char_t* name_)
    {
        return remove_child(child(name_));
    }

    PUGI__FN bool xml_node::remove_child(const xml_node& n)
    {
        if (!_root || !n._root || n._root->parent != _root) return false;

        impl::xml_allocator& alloc = impl::get_allocator(_root);
        if (!alloc.reserve()) return false;

        impl::remove_node(n._root);
        impl::destroy_node(n._root, alloc);

        return true;
    }

    PUGI__FN xml_parse_result xml_node::append_buffer(const void* contents, size_t size, unsigned int options, xml_encoding encoding)
    {
        // append_buffer is only valid for elements/documents
        if (!impl::allow_insert_child(type(), node_element)) return impl::make_parse_result(status_append_invalid_root);

        // get document node
        impl::xml_document_struct* doc = &impl::get_document(_root);

        // disable document_buffer_order optimization since in a document with multiple buffers comparing buffer pointers does not make
        // sense
        doc->header |= impl::xml_memory_page_contents_shared_mask;

        // get extra buffer element (we'll store the document fragment buffer there so that we can deallocate it later)
        impl::xml_memory_page*  page = 0;
        impl::xml_extra_buffer* extra =
            static_cast<impl::xml_extra_buffer*>(doc->allocate_memory(sizeof(impl::xml_extra_buffer) + sizeof(void*), page));
        (void)page;

        if (!extra) return impl::make_parse_result(status_out_of_memory);

#    ifdef PUGIXML_COMPACT
        // align the memory block to a pointer boundary; this is required for compact mode where memory allocations are only 4b aligned
        // note that this requires up to sizeof(void*)-1 additional memory, which the allocation above takes into account
        extra =
            reinterpret_cast<impl::xml_extra_buffer*>((reinterpret_cast<uintptr_t>(extra) + (sizeof(void*) - 1)) & ~(sizeof(void*) - 1));
#    endif

        // add extra buffer to the list
        extra->buffer      = 0;
        extra->next        = doc->extra_buffers;
        doc->extra_buffers = extra;

        // name of the root has to be NULL before parsing - otherwise closing node mismatches will not be detected at the top level
        impl::name_null_sentry sentry(_root);

        return impl::load_buffer_impl(doc, _root, const_cast<void*>(contents), size, options, encoding, false, false, &extra->buffer);
    }

    PUGI__FN xml_node xml_node::find_child_by_attribute(const char_t* name_, const char_t* attr_name, const char_t* attr_value) const
    {
        if (!_root) return xml_node();

        for (xml_node_struct* i = _root->first_child; i; i = i->next_sibling)
            if (i->name && impl::strequal(name_, i->name)) {
                for (xml_attribute_struct* a = i->first_attribute; a; a = a->next_attribute)
                    if (a->name && impl::strequal(attr_name, a->name) &&
                        impl::strequal(attr_value, a->value ? a->value + 0 : PUGIXML_TEXT("")))
                        return xml_node(i);
            }

        return xml_node();
    }

    PUGI__FN xml_node xml_node::find_child_by_attribute(const char_t* attr_name, const char_t* attr_value) const
    {
        if (!_root) return xml_node();

        for (xml_node_struct* i = _root->first_child; i; i = i->next_sibling)
            for (xml_attribute_struct* a = i->first_attribute; a; a = a->next_attribute)
                if (a->name && impl::strequal(attr_name, a->name) && impl::strequal(attr_value, a->value ? a->value + 0 : PUGIXML_TEXT("")))
                    return xml_node(i);

        return xml_node();
    }

#    ifndef PUGIXML_NO_STL
    PUGI__FN string_t xml_node::path(char_t delimiter) const
    {
        if (!_root) return string_t();

        size_t offset = 0;

        for (xml_node_struct* i = _root; i; i = i->parent) {
            offset += (i != _root);
            offset += i->name ? impl::strlength(i->name) : 0;
        }

        string_t result;
        result.resize(offset);

        for (xml_node_struct* j = _root; j; j = j->parent) {
            if (j != _root) result[--offset] = delimiter;

            if (j->name) {
                size_t length = impl::strlength(j->name);

                offset -= length;
                memcpy(&result[offset], j->name, length * sizeof(char_t));
            }
        }

        assert(offset == 0);

        return result;
    }
#    endif

    PUGI__FN xml_node xml_node::first_element_by_path(const char_t* path_, char_t delimiter) const
    {
        xml_node found = *this;    // Current search context.

        if (!_root || !path_[0]) return found;

        if (path_[0] == delimiter) {
            // Absolute path; e.g. '/foo/bar'
            found = found.root();
            ++path_;
        }

        const char_t* path_segment = path_;

        while (*path_segment == delimiter) ++path_segment;

        const char_t* path_segment_end = path_segment;

        while (*path_segment_end && *path_segment_end != delimiter) ++path_segment_end;

        if (path_segment == path_segment_end) return found;

        const char_t* next_segment = path_segment_end;

        while (*next_segment == delimiter) ++next_segment;

        if (*path_segment == '.' && path_segment + 1 == path_segment_end)
            return found.first_element_by_path(next_segment, delimiter);
        else if (*path_segment == '.' && *(path_segment + 1) == '.' && path_segment + 2 == path_segment_end)
            return found.parent().first_element_by_path(next_segment, delimiter);
        else {
            for (xml_node_struct* j = found._root->first_child; j; j = j->next_sibling) {
                if (j->name && impl::strequalrange(j->name, path_segment, static_cast<size_t>(path_segment_end - path_segment))) {
                    xml_node subsearch = xml_node(j).first_element_by_path(next_segment, delimiter);

                    if (subsearch) return subsearch;
                }
            }

            return xml_node();
        }
    }

    PUGI__FN bool xml_node::traverse(xml_tree_walker& walker)
    {
        walker._depth = -1;

        xml_node arg_begin(_root);
        if (!walker.begin(arg_begin)) return false;

        xml_node_struct* cur = _root ? _root->first_child + 0 : 0;

        if (cur) {
            ++walker._depth;

            do {
                xml_node arg_for_each(cur);
                if (!walker.for_each(arg_for_each)) return false;

                if (cur->first_child) {
                    ++walker._depth;
                    cur = cur->first_child;
                }
                else if (cur->next_sibling)
                    cur = cur->next_sibling;
                else {
                    while (!cur->next_sibling && cur != _root && cur->parent) {
                        --walker._depth;
                        cur = cur->parent;
                    }

                    if (cur != _root) cur = cur->next_sibling;
                }
            }
            while (cur && cur != _root);
        }

        assert(walker._depth == -1);

        xml_node arg_end(_root);
        return walker.end(arg_end);
    }

    PUGI__FN size_t xml_node::hash_value() const
    {
        return static_cast<size_t>(reinterpret_cast<uintptr_t>(_root) / sizeof(xml_node_struct));
    }

    PUGI__FN xml_node_struct* xml_node::internal_object() const
    {
        return _root;
    }

    PUGI__FN void
        xml_node::print(xml_writer& writer, const char_t* indent, unsigned int flags, xml_encoding encoding, unsigned int depth) const
    {
        if (!_root) return;

        impl::xml_buffered_writer buffered_writer(writer, encoding);

        impl::node_output(buffered_writer, _root, indent, flags, depth);

        buffered_writer.flush();
    }

#    ifndef PUGIXML_NO_STL
    PUGI__FN void xml_node::print(std::basic_ostream<char, std::char_traits<char> >& stream,
                                  const char_t*                                     indent,
                                  unsigned int                                      flags,
                                  xml_encoding                                      encoding,
                                  unsigned int                                      depth) const
    {
        xml_writer_stream writer(stream);

        print(writer, indent, flags, encoding, depth);
    }

    PUGI__FN void xml_node::print(std::basic_ostream<wchar_t, std::char_traits<wchar_t> >& stream,
                                  const char_t*                                           indent,
                                  unsigned int                                            flags,
                                  unsigned int                                            depth) const
    {
        xml_writer_stream writer(stream);

        print(writer, indent, flags, encoding_wchar, depth);
    }
#    endif

    PUGI__FN ptrdiff_t xml_node::offset_debug() const
    {
        if (!_root) return -1;

        impl::xml_document_struct& doc = impl::get_document(_root);

        // we can determine the offset reliably only if there is exactly once parse buffer
        if (!doc.buffer || doc.extra_buffers) return -1;

        switch (type()) {
            case node_document:
                return 0;

            case node_element:
            case node_declaration:
            case node_pi:
                return _root->name && (_root->header & impl::xml_memory_page_name_allocated_or_shared_mask) == 0 ? _root->name - doc.buffer
                                                                                                                 : -1;

            case node_pcdata:
            case node_cdata:
            case node_comment:
            case node_doctype:
                return _root->value && (_root->header & impl::xml_memory_page_value_allocated_or_shared_mask) == 0
                           ? _root->value - doc.buffer
                           : -1;

            default:
                assert(false && "Invalid node type");    // unreachable
                return -1;
        }
    }

#    ifdef __BORLANDC__
    PUGI__FN bool operator&&(const xml_node& lhs, bool rhs)
    {
        return (bool)lhs && rhs;
    }

    PUGI__FN bool operator||(const xml_node& lhs, bool rhs)
    {
        return (bool)lhs || rhs;
    }
#    endif

    PUGI__FN xml_text::xml_text(xml_node_struct* root) : _root(root) {}

    PUGI__FN xml_node_struct* xml_text::_data() const
    {
        if (!_root || impl::is_text_node(_root)) return _root;

        // element nodes can have value if parse_embed_pcdata was used
        if (PUGI__NODETYPE(_root) == node_element && _root->value) return _root;

        for (xml_node_struct* node = _root->first_child; node; node = node->next_sibling)
            if (impl::is_text_node(node)) return node;

        return 0;
    }

    PUGI__FN xml_node_struct* xml_text::_data_new()
    {
        xml_node_struct* d = _data();
        if (d) return d;

        return xml_node(_root).append_child(node_pcdata).internal_object();
    }

    PUGI__FN xml_text::xml_text() : _root(0) {}

    PUGI__FN static void unspecified_bool_xml_text(xml_text***) {}

    PUGI__FN xml_text::operator xml_text::unspecified_bool_type() const
    {
        return _data() ? unspecified_bool_xml_text : 0;
    }

    PUGI__FN bool xml_text::operator!() const
    {
        return !_data();
    }

    PUGI__FN bool xml_text::empty() const
    {
        return _data() == 0;
    }

    PUGI__FN const char_t* xml_text::get() const
    {
        xml_node_struct* d = _data();

        return (d && d->value) ? d->value + 0 : PUGIXML_TEXT("");
    }

    PUGI__FN const char_t* xml_text::as_string(const char_t* def) const
    {
        xml_node_struct* d = _data();

        return (d && d->value) ? d->value + 0 : def;
    }

    PUGI__FN int xml_text::as_int(int def) const
    {
        xml_node_struct* d = _data();

        return (d && d->value) ? impl::get_value_int(d->value) : def;
    }

    PUGI__FN unsigned int xml_text::as_uint(unsigned int def) const
    {
        xml_node_struct* d = _data();

        return (d && d->value) ? impl::get_value_uint(d->value) : def;
    }

    PUGI__FN double xml_text::as_double(double def) const
    {
        xml_node_struct* d = _data();

        return (d && d->value) ? impl::get_value_double(d->value) : def;
    }

    PUGI__FN float xml_text::as_float(float def) const
    {
        xml_node_struct* d = _data();

        return (d && d->value) ? impl::get_value_float(d->value) : def;
    }

    PUGI__FN bool xml_text::as_bool(bool def) const
    {
        xml_node_struct* d = _data();

        return (d && d->value) ? impl::get_value_bool(d->value) : def;
    }

#    ifdef PUGIXML_HAS_LONG_LONG
    PUGI__FN long long xml_text::as_llong(long long def) const
    {
        xml_node_struct* d = _data();

        return (d && d->value) ? impl::get_value_llong(d->value) : def;
    }

    PUGI__FN unsigned long long xml_text::as_ullong(unsigned long long def) const
    {
        xml_node_struct* d = _data();

        return (d && d->value) ? impl::get_value_ullong(d->value) : def;
    }
#    endif

    PUGI__FN bool xml_text::set(const char_t* rhs)
    {
        xml_node_struct* dn = _data_new();

        return dn ? impl::strcpy_insitu(dn->value, dn->header, impl::xml_memory_page_value_allocated_mask, rhs, impl::strlength(rhs))
                  : false;
    }

    PUGI__FN bool xml_text::set(int rhs)
    {
        xml_node_struct* dn = _data_new();

        return dn ? impl::set_value_integer<unsigned int>(dn->value, dn->header, impl::xml_memory_page_value_allocated_mask, rhs, rhs < 0)
                  : false;
    }

    PUGI__FN bool xml_text::set(unsigned int rhs)
    {
        xml_node_struct* dn = _data_new();

        return dn ? impl::set_value_integer<unsigned int>(dn->value, dn->header, impl::xml_memory_page_value_allocated_mask, rhs, false)
                  : false;
    }

    PUGI__FN bool xml_text::set(long rhs)
    {
        xml_node_struct* dn = _data_new();

        return dn ? impl::set_value_integer<unsigned long>(dn->value, dn->header, impl::xml_memory_page_value_allocated_mask, rhs, rhs < 0)
                  : false;
    }

    PUGI__FN bool xml_text::set(unsigned long rhs)
    {
        xml_node_struct* dn = _data_new();

        return dn ? impl::set_value_integer<unsigned long>(dn->value, dn->header, impl::xml_memory_page_value_allocated_mask, rhs, false)
                  : false;
    }

    PUGI__FN bool xml_text::set(float rhs)
    {
        xml_node_struct* dn = _data_new();

        return dn ? impl::set_value_convert(dn->value, dn->header, impl::xml_memory_page_value_allocated_mask, rhs) : false;
    }

    PUGI__FN bool xml_text::set(double rhs)
    {
        xml_node_struct* dn = _data_new();

        return dn ? impl::set_value_convert(dn->value, dn->header, impl::xml_memory_page_value_allocated_mask, rhs) : false;
    }

    PUGI__FN bool xml_text::set(bool rhs)
    {
        xml_node_struct* dn = _data_new();

        return dn ? impl::set_value_bool(dn->value, dn->header, impl::xml_memory_page_value_allocated_mask, rhs) : false;
    }

#    ifdef PUGIXML_HAS_LONG_LONG
    PUGI__FN bool xml_text::set(long long rhs)
    {
        xml_node_struct* dn = _data_new();

        return dn ? impl::set_value_integer<unsigned long long>(dn->value,
                                                                dn->header,
                                                                impl::xml_memory_page_value_allocated_mask,
                                                                rhs,
                                                                rhs < 0)
                  : false;
    }

    PUGI__FN bool xml_text::set(unsigned long long rhs)
    {
        xml_node_struct* dn = _data_new();

        return dn ? impl::set_value_integer<unsigned long long>(dn->value,
                                                                dn->header,
                                                                impl::xml_memory_page_value_allocated_mask,
                                                                rhs,
                                                                false)
                  : false;
    }
#    endif

    PUGI__FN xml_text& xml_text::operator=(const char_t* rhs)
    {
        set(rhs);
        return *this;
    }

    PUGI__FN xml_text& xml_text::operator=(int rhs)
    {
        set(rhs);
        return *this;
    }

    PUGI__FN xml_text& xml_text::operator=(unsigned int rhs)
    {
        set(rhs);
        return *this;
    }

    PUGI__FN xml_text& xml_text::operator=(long rhs)
    {
        set(rhs);
        return *this;
    }

    PUGI__FN xml_text& xml_text::operator=(unsigned long rhs)
    {
        set(rhs);
        return *this;
    }

    PUGI__FN xml_text& xml_text::operator=(double rhs)
    {
        set(rhs);
        return *this;
    }

    PUGI__FN xml_text& xml_text::operator=(float rhs)
    {
        set(rhs);
        return *this;
    }

    PUGI__FN xml_text& xml_text::operator=(bool rhs)
    {
        set(rhs);
        return *this;
    }

#    ifdef PUGIXML_HAS_LONG_LONG
    PUGI__FN xml_text& xml_text::operator=(long long rhs)
    {
        set(rhs);
        return *this;
    }

    PUGI__FN xml_text& xml_text::operator=(unsigned long long rhs)
    {
        set(rhs);
        return *this;
    }
#    endif

    PUGI__FN xml_node xml_text::data() const
    {
        return xml_node(_data());
    }

#    ifdef __BORLANDC__
    PUGI__FN bool operator&&(const xml_text& lhs, bool rhs)
    {
        return (bool)lhs && rhs;
    }

    PUGI__FN bool operator||(const xml_text& lhs, bool rhs)
    {
        return (bool)lhs || rhs;
    }
#    endif

    PUGI__FN xml_node_iterator::xml_node_iterator() {}

    PUGI__FN xml_node_iterator::xml_node_iterator(const xml_node& node) : _wrap(node), _parent(node.parent()) {}

    PUGI__FN xml_node_iterator::xml_node_iterator(xml_node_struct* ref, xml_node_struct* parent) : _wrap(ref), _parent(parent) {}

    PUGI__FN bool xml_node_iterator::operator==(const xml_node_iterator& rhs) const
    {
        return _wrap._root == rhs._wrap._root && _parent._root == rhs._parent._root;
    }

    PUGI__FN bool xml_node_iterator::operator!=(const xml_node_iterator& rhs) const
    {
        return _wrap._root != rhs._wrap._root || _parent._root != rhs._parent._root;
    }

    PUGI__FN xml_node& xml_node_iterator::operator*() const
    {
        assert(_wrap._root);
        return _wrap;
    }

    PUGI__FN xml_node* xml_node_iterator::operator->() const
    {
        assert(_wrap._root);
        return const_cast<xml_node*>(&_wrap);    // BCC5 workaround
    }

    PUGI__FN const xml_node_iterator& xml_node_iterator::operator++()
    {
        assert(_wrap._root);
        _wrap._root = _wrap._root->next_sibling;
        return *this;
    }

    PUGI__FN xml_node_iterator xml_node_iterator::operator++(int)
    {
        xml_node_iterator temp = *this;
        ++*this;
        return temp;
    }

    PUGI__FN const xml_node_iterator& xml_node_iterator::operator--()
    {
        _wrap = _wrap._root ? _wrap.previous_sibling() : _parent.last_child();
        return *this;
    }

    PUGI__FN xml_node_iterator xml_node_iterator::operator--(int)
    {
        xml_node_iterator temp = *this;
        --*this;
        return temp;
    }

    PUGI__FN xml_attribute_iterator::xml_attribute_iterator() {}

    PUGI__FN xml_attribute_iterator::xml_attribute_iterator(const xml_attribute& attr, const xml_node& parent)
        : _wrap(attr),
          _parent(parent)
    {}

    PUGI__FN xml_attribute_iterator::xml_attribute_iterator(xml_attribute_struct* ref, xml_node_struct* parent)
        : _wrap(ref),
          _parent(parent)
    {}

    PUGI__FN bool xml_attribute_iterator::operator==(const xml_attribute_iterator& rhs) const
    {
        return _wrap._attr == rhs._wrap._attr && _parent._root == rhs._parent._root;
    }

    PUGI__FN bool xml_attribute_iterator::operator!=(const xml_attribute_iterator& rhs) const
    {
        return _wrap._attr != rhs._wrap._attr || _parent._root != rhs._parent._root;
    }

    PUGI__FN xml_attribute& xml_attribute_iterator::operator*() const
    {
        assert(_wrap._attr);
        return _wrap;
    }

    PUGI__FN xml_attribute* xml_attribute_iterator::operator->() const
    {
        assert(_wrap._attr);
        return const_cast<xml_attribute*>(&_wrap);    // BCC5 workaround
    }

    PUGI__FN const xml_attribute_iterator& xml_attribute_iterator::operator++()
    {
        assert(_wrap._attr);
        _wrap._attr = _wrap._attr->next_attribute;
        return *this;
    }

    PUGI__FN xml_attribute_iterator xml_attribute_iterator::operator++(int)
    {
        xml_attribute_iterator temp = *this;
        ++*this;
        return temp;
    }

    PUGI__FN const xml_attribute_iterator& xml_attribute_iterator::operator--()
    {
        _wrap = _wrap._attr ? _wrap.previous_attribute() : _parent.last_attribute();
        return *this;
    }

    PUGI__FN xml_attribute_iterator xml_attribute_iterator::operator--(int)
    {
        xml_attribute_iterator temp = *this;
        --*this;
        return temp;
    }

    PUGI__FN xml_named_node_iterator::xml_named_node_iterator() : _name(0) {}

    PUGI__FN xml_named_node_iterator::xml_named_node_iterator(const xml_node& node, const char_t* name)
        : _wrap(node),
          _parent(node.parent()),
          _name(name)
    {}

    PUGI__FN xml_named_node_iterator::xml_named_node_iterator(xml_node_struct* ref, xml_node_struct* parent, const char_t* name)
        : _wrap(ref),
          _parent(parent),
          _name(name)
    {}

    PUGI__FN bool xml_named_node_iterator::operator==(const xml_named_node_iterator& rhs) const
    {
        return _wrap._root == rhs._wrap._root && _parent._root == rhs._parent._root;
    }

    PUGI__FN bool xml_named_node_iterator::operator!=(const xml_named_node_iterator& rhs) const
    {
        return _wrap._root != rhs._wrap._root || _parent._root != rhs._parent._root;
    }

    PUGI__FN xml_node& xml_named_node_iterator::operator*() const
    {
        assert(_wrap._root);
        return _wrap;
    }

    PUGI__FN xml_node* xml_named_node_iterator::operator->() const
    {
        assert(_wrap._root);
        return const_cast<xml_node*>(&_wrap);    // BCC5 workaround
    }

    PUGI__FN const xml_named_node_iterator& xml_named_node_iterator::operator++()
    {
        assert(_wrap._root);
        _wrap = _wrap.next_sibling(_name);
        return *this;
    }

    PUGI__FN xml_named_node_iterator xml_named_node_iterator::operator++(int)
    {
        xml_named_node_iterator temp = *this;
        ++*this;
        return temp;
    }

    PUGI__FN const xml_named_node_iterator& xml_named_node_iterator::operator--()
    {
        if (_wrap._root)
            _wrap = _wrap.previous_sibling(_name);
        else {
            _wrap = _parent.last_child();

            if (!impl::strequal(_wrap.name(), _name)) _wrap = _wrap.previous_sibling(_name);
        }

        return *this;
    }

    PUGI__FN xml_named_node_iterator xml_named_node_iterator::operator--(int)
    {
        xml_named_node_iterator temp = *this;
        --*this;
        return temp;
    }

    PUGI__FN xml_parse_result::xml_parse_result() : status(status_internal_error), offset(0), encoding(encoding_auto) {}

    PUGI__FN xml_parse_result::operator bool() const
    {
        return status == status_ok;
    }

    PUGI__FN const char* xml_parse_result::description() const
    {
        switch (status) {
            case status_ok:
                return "No error";

            case status_file_not_found:
                return "File was not found";
            case status_io_error:
                return "Error reading from file/stream";
            case status_out_of_memory:
                return "Could not allocate memory";
            case status_internal_error:
                return "Internal error occurred";

            case status_unrecognized_tag:
                return "Could not determine tag type";

            case status_bad_pi:
                return "Error parsing document declaration/processing instruction";
            case status_bad_comment:
                return "Error parsing comment";
            case status_bad_cdata:
                return "Error parsing CDATA section";
            case status_bad_doctype:
                return "Error parsing document type declaration";
            case status_bad_pcdata:
                return "Error parsing PCDATA section";
            case status_bad_start_element:
                return "Error parsing start element tag";
            case status_bad_attribute:
                return "Error parsing element attribute";
            case status_bad_end_element:
                return "Error parsing end element tag";
            case status_end_element_mismatch:
                return "Start-end tags mismatch";

            case status_append_invalid_root:
                return "Unable to append nodes: root is not an element or document";

            case status_no_document_element:
                return "No document element found";

            default:
                return "Unknown error";
        }
    }

    PUGI__FN xml_document::xml_document() : _buffer(0)
    {
        _create();
    }

    PUGI__FN xml_document::~xml_document()
    {
        _destroy();
    }

#    ifdef PUGIXML_HAS_MOVE
    PUGI__FN xml_document::xml_document(xml_document&& rhs) PUGIXML_NOEXCEPT_IF_NOT_COMPACT : _buffer(0)
    {
        _create();
        _move(rhs);
    }

    PUGI__FN xml_document& xml_document::operator=(xml_document&& rhs) PUGIXML_NOEXCEPT_IF_NOT_COMPACT
    {
        if (this == &rhs) return *this;

        _destroy();
        _create();
        _move(rhs);

        return *this;
    }
#    endif

    PUGI__FN void xml_document::reset()
    {
        _destroy();
        _create();
    }

    PUGI__FN void xml_document::reset(const xml_document& proto)
    {
        reset();

        for (xml_node cur = proto.first_child(); cur; cur = cur.next_sibling()) append_copy(cur);
    }

    PUGI__FN void xml_document::_create()
    {
        assert(!_root);

#    ifdef PUGIXML_COMPACT
        // space for page marker for the first page (uint32_t), rounded up to pointer size; assumes pointers are at least 32-bit
        const size_t page_offset = sizeof(void*);
#    else
        const size_t page_offset = 0;
#    endif

        // initialize sentinel page
        PUGI__STATIC_ASSERT(sizeof(impl::xml_memory_page) + sizeof(impl::xml_document_struct) + page_offset <= sizeof(_memory));

        // prepare page structure
        impl::xml_memory_page* page = impl::xml_memory_page::construct(_memory);
        assert(page);

        page->busy_size = impl::xml_memory_page_size;

        // setup first page marker
#    ifdef PUGIXML_COMPACT
        // round-trip through void* to avoid 'cast increases required alignment of target type' warning
        page->compact_page_marker =
            reinterpret_cast<uint32_t*>(static_cast<void*>(reinterpret_cast<char*>(page) + sizeof(impl::xml_memory_page)));
        *page->compact_page_marker = sizeof(impl::xml_memory_page);
#    endif

        // allocate new root
        _root = new (reinterpret_cast<char*>(page) + sizeof(impl::xml_memory_page) + page_offset) impl::xml_document_struct(page);
        _root->prev_sibling_c = _root;

        // setup sentinel page
        page->allocator = static_cast<impl::xml_document_struct*>(_root);

        // setup hash table pointer in allocator
#    ifdef PUGIXML_COMPACT
        page->allocator->_hash = &static_cast<impl::xml_document_struct*>(_root)->hash;
#    endif

        // verify the document allocation
        assert(reinterpret_cast<char*>(_root) + sizeof(impl::xml_document_struct) <= _memory + sizeof(_memory));
    }

    PUGI__FN void xml_document::_destroy()
    {
        assert(_root);

        // destroy static storage
        if (_buffer) {
            impl::xml_memory::deallocate(_buffer);
            _buffer = 0;
        }

        // destroy extra buffers (note: no need to destroy linked list nodes, they're allocated using document allocator)
        for (impl::xml_extra_buffer* extra = static_cast<impl::xml_document_struct*>(_root)->extra_buffers; extra; extra = extra->next) {
            if (extra->buffer) impl::xml_memory::deallocate(extra->buffer);
        }

        // destroy dynamic storage, leave sentinel page (it's in static memory)
        impl::xml_memory_page* root_page = PUGI__GETPAGE(_root);
        assert(root_page && !root_page->prev);
        assert(reinterpret_cast<char*>(root_page) >= _memory && reinterpret_cast<char*>(root_page) < _memory + sizeof(_memory));

        for (impl::xml_memory_page* page = root_page->next; page;) {
            impl::xml_memory_page* next = page->next;

            impl::xml_allocator::deallocate_page(page);

            page = next;
        }

#    ifdef PUGIXML_COMPACT
        // destroy hash table
        static_cast<impl::xml_document_struct*>(_root)->hash.clear();
#    endif

        _root = 0;
    }

#    ifdef PUGIXML_HAS_MOVE
    PUGI__FN void xml_document::_move(xml_document& rhs) PUGIXML_NOEXCEPT_IF_NOT_COMPACT
    {
        impl::xml_document_struct* doc   = static_cast<impl::xml_document_struct*>(_root);
        impl::xml_document_struct* other = static_cast<impl::xml_document_struct*>(rhs._root);

        // save first child pointer for later; this needs hash access
        xml_node_struct* other_first_child = other->first_child;

#        ifdef PUGIXML_COMPACT
        // reserve space for the hash table up front; this is the only operation that can fail
        // if it does, we have no choice but to throw (if we have exceptions)
        if (other_first_child) {
            size_t other_children = 0;
            for (xml_node_struct* node = other_first_child; node; node = node->next_sibling) other_children++;

            // in compact mode, each pointer assignment could result in a hash table request
            // during move, we have to relocate document first_child and parents of all children
            // normally there's just one child and its parent has a pointerless encoding but
            // we assume the worst here
            if (!other->_hash->reserve(other_children + 1)) {
#            ifdef PUGIXML_NO_EXCEPTIONS
                return;
#            else
                throw std::bad_alloc();
#            endif
            }
        }
#        endif

        // move allocation state
        doc->_root      = other->_root;
        doc->_busy_size = other->_busy_size;

        // move buffer state
        doc->buffer        = other->buffer;
        doc->extra_buffers = other->extra_buffers;
        _buffer            = rhs._buffer;

#        ifdef PUGIXML_COMPACT
        // move compact hash; note that the hash table can have pointers to other but they will be "inactive", similarly to nodes removed
        // with remove_child
        doc->hash  = other->hash;
        doc->_hash = &doc->hash;

        // make sure we don't access other hash up until the end when we reinitialize other document
        other->_hash = 0;
#        endif

        // move page structure
        impl::xml_memory_page* doc_page = PUGI__GETPAGE(doc);
        assert(doc_page && !doc_page->prev && !doc_page->next);

        impl::xml_memory_page* other_page = PUGI__GETPAGE(other);
        assert(other_page && !other_page->prev);

        // relink pages since root page is embedded into xml_document
        if (impl::xml_memory_page* page = other_page->next) {
            assert(page->prev == other_page);

            page->prev = doc_page;

            doc_page->next   = page;
            other_page->next = 0;
        }

        // make sure pages point to the correct document state
        for (impl::xml_memory_page* page = doc_page->next; page; page = page->next) {
            assert(page->allocator == other);

            page->allocator = doc;

#        ifdef PUGIXML_COMPACT
            // this automatically migrates most children between documents and prevents ->parent assignment from allocating
            if (page->compact_shared_parent == other) page->compact_shared_parent = doc;
#        endif
        }

        // move tree structure
        assert(!doc->first_child);

        doc->first_child = other_first_child;

        for (xml_node_struct* node = other_first_child; node; node = node->next_sibling) {
#        ifdef PUGIXML_COMPACT
            // most children will have migrated when we reassigned compact_shared_parent
            assert(node->parent == other || node->parent == doc);

            node->parent = doc;
#        else
            assert(node->parent == other);
            node->parent = doc;
#        endif
        }

        // reset other document
        new (other) impl::xml_document_struct(PUGI__GETPAGE(other));
        rhs._buffer = 0;
    }
#    endif

#    ifndef PUGIXML_NO_STL
    PUGI__FN xml_parse_result xml_document::load(std::basic_istream<char, std::char_traits<char> >& stream,
                                                 unsigned int                                      options,
                                                 xml_encoding                                      encoding)
    {
        reset();

        return impl::load_stream_impl(static_cast<impl::xml_document_struct*>(_root), stream, options, encoding, &_buffer);
    }

    PUGI__FN xml_parse_result xml_document::load(std::basic_istream<wchar_t, std::char_traits<wchar_t> >& stream, unsigned int options)
    {
        reset();

        return impl::load_stream_impl(static_cast<impl::xml_document_struct*>(_root), stream, options, encoding_wchar, &_buffer);
    }
#    endif

    PUGI__FN xml_parse_result xml_document::load_string(const char_t* contents, unsigned int options)
    {
        // Force native encoding (skip autodetection)
#    ifdef PUGIXML_WCHAR_MODE
        xml_encoding encoding = encoding_wchar;
#    else
        xml_encoding encoding = encoding_utf8;
#    endif

        return load_buffer(contents, impl::strlength(contents) * sizeof(char_t), options, encoding);
    }

    PUGI__FN xml_parse_result xml_document::load(const char_t* contents, unsigned int options)
    {
        return load_string(contents, options);
    }

    PUGI__FN xml_parse_result xml_document::load_file(const char* path_, unsigned int options, xml_encoding encoding)
    {
        reset();

        using impl::auto_deleter;    // MSVC7 workaround
        auto_deleter<FILE> file(fopen(path_, "rb"), impl::close_file);

        return impl::load_file_impl(static_cast<impl::xml_document_struct*>(_root), file.data, options, encoding, &_buffer);
    }

    PUGI__FN xml_parse_result xml_document::load_file(const wchar_t* path_, unsigned int options, xml_encoding encoding)
    {
        reset();

        using impl::auto_deleter;    // MSVC7 workaround
        auto_deleter<FILE> file(impl::open_file_wide(path_, L"rb"), impl::close_file);

        return impl::load_file_impl(static_cast<impl::xml_document_struct*>(_root), file.data, options, encoding, &_buffer);
    }

    PUGI__FN xml_parse_result xml_document::load_buffer(const void* contents, size_t size, unsigned int options, xml_encoding encoding)
    {
        reset();

        return impl::load_buffer_impl(static_cast<impl::xml_document_struct*>(_root),
                                      _root,
                                      const_cast<void*>(contents),
                                      size,
                                      options,
                                      encoding,
                                      false,
                                      false,
                                      &_buffer);
    }

    PUGI__FN xml_parse_result xml_document::load_buffer_inplace(void* contents, size_t size, unsigned int options, xml_encoding encoding)
    {
        reset();

        return impl::load_buffer_impl(static_cast<impl::xml_document_struct*>(_root),
                                      _root,
                                      contents,
                                      size,
                                      options,
                                      encoding,
                                      true,
                                      false,
                                      &_buffer);
    }

    PUGI__FN xml_parse_result xml_document::load_buffer_inplace_own(void*        contents,
                                                                    size_t       size,
                                                                    unsigned int options,
                                                                    xml_encoding encoding)
    {
        reset();

        return impl::load_buffer_impl(static_cast<impl::xml_document_struct*>(_root),
                                      _root,
                                      contents,
                                      size,
                                      options,
                                      encoding,
                                      true,
                                      true,
                                      &_buffer);
    }

    PUGI__FN void xml_document::save(xml_writer& writer, const char_t* indent, unsigned int flags, xml_encoding encoding) const
    {
        impl::xml_buffered_writer buffered_writer(writer, encoding);

        if ((flags & format_write_bom) && encoding != encoding_latin1) {
            // BOM always represents the codepoint U+FEFF, so just write it in native encoding
#    ifdef PUGIXML_WCHAR_MODE
            unsigned int bom = 0xfeff;
            buffered_writer.write(static_cast<wchar_t>(bom));
#    else
            buffered_writer.write('\xef', '\xbb', '\xbf');
#    endif
        }

        if (!(flags & format_no_declaration) && !impl::has_declaration(_root)) {
            buffered_writer.write_string(PUGIXML_TEXT("<?xml version=\"1.0\""));
            if (encoding == encoding_latin1) buffered_writer.write_string(PUGIXML_TEXT(" encoding=\"ISO-8859-1\""));
            buffered_writer.write('?', '>');
            if (!(flags & format_raw)) buffered_writer.write('\n');
        }

        impl::node_output(buffered_writer, _root, indent, flags, 0);

        buffered_writer.flush();
    }

#    ifndef PUGIXML_NO_STL
    PUGI__FN void xml_document::save(std::basic_ostream<char, std::char_traits<char> >& stream,
                                     const char_t*                                     indent,
                                     unsigned int                                      flags,
                                     xml_encoding                                      encoding) const
    {
        xml_writer_stream writer(stream);

        save(writer, indent, flags, encoding);
    }

    PUGI__FN void
        xml_document::save(std::basic_ostream<wchar_t, std::char_traits<wchar_t> >& stream, const char_t* indent, unsigned int flags) const
    {
        xml_writer_stream writer(stream);

        save(writer, indent, flags, encoding_wchar);
    }
#    endif

    PUGI__FN bool xml_document::save_file(const char* path_, const char_t* indent, unsigned int flags, xml_encoding encoding) const
    {
        using impl::auto_deleter;    // MSVC7 workaround
        auto_deleter<FILE> file(fopen(path_, (flags & format_save_file_text) ? "w" : "wb"), impl::close_file);

        return impl::save_file_impl(*this, file.data, indent, flags, encoding);
    }

    PUGI__FN bool xml_document::save_file(const wchar_t* path_, const char_t* indent, unsigned int flags, xml_encoding encoding) const
    {
        using impl::auto_deleter;    // MSVC7 workaround
        auto_deleter<FILE> file(impl::open_file_wide(path_, (flags & format_save_file_text) ? L"w" : L"wb"), impl::close_file);

        return impl::save_file_impl(*this, file.data, indent, flags, encoding);
    }

    PUGI__FN xml_node xml_document::document_element() const
    {
        assert(_root);

        for (xml_node_struct* i = _root->first_child; i; i = i->next_sibling)
            if (PUGI__NODETYPE(i) == node_element) return xml_node(i);

        return xml_node();
    }

#    ifndef PUGIXML_NO_STL
    PUGI__FN std::string PUGIXML_FUNCTION as_utf8(const wchar_t* str)
    {
        assert(str);

        return impl::as_utf8_impl(str, impl::strlength_wide(str));
    }

    PUGI__FN std::string PUGIXML_FUNCTION as_utf8(const std::basic_string<wchar_t>& str)
    {
        return impl::as_utf8_impl(str.c_str(), str.size());
    }

    PUGI__FN std::basic_string<wchar_t> PUGIXML_FUNCTION as_wide(const char* str)
    {
        assert(str);

        return impl::as_wide_impl(str, strlen(str));
    }

    PUGI__FN std::basic_string<wchar_t> PUGIXML_FUNCTION as_wide(const std::string& str)
    {
        return impl::as_wide_impl(str.c_str(), str.size());
    }
#    endif

    PUGI__FN void PUGIXML_FUNCTION set_memory_management_functions(allocation_function allocate, deallocation_function deallocate)
    {
        impl::xml_memory::allocate   = allocate;
        impl::xml_memory::deallocate = deallocate;
    }

    PUGI__FN allocation_function PUGIXML_FUNCTION get_memory_allocation_function()
    {
        return impl::xml_memory::allocate;
    }

    PUGI__FN deallocation_function PUGIXML_FUNCTION get_memory_deallocation_function()
    {
        return impl::xml_memory::deallocate;
    }
}    // namespace pugi

#    if !defined(PUGIXML_NO_STL) && (defined(_MSC_VER) || defined(__ICC))
namespace std
{
    // Workarounds for (non-standard) iterator category detection for older versions (MSVC7/IC8 and earlier)
    PUGI__FN std::bidirectional_iterator_tag _Iter_cat(const pugi::xml_node_iterator&)
    {
        return std::bidirectional_iterator_tag();
    }

    PUGI__FN std::bidirectional_iterator_tag _Iter_cat(const pugi::xml_attribute_iterator&)
    {
        return std::bidirectional_iterator_tag();
    }

    PUGI__FN std::bidirectional_iterator_tag _Iter_cat(const pugi::xml_named_node_iterator&)
    {
        return std::bidirectional_iterator_tag();
    }
}    // namespace std
#    endif

#    if !defined(PUGIXML_NO_STL) && defined(__SUNPRO_CC)
namespace std
{
    // Workarounds for (non-standard) iterator category detection
    PUGI__FN std::bidirectional_iterator_tag __iterator_category(const pugi::xml_node_iterator&)
    {
        return std::bidirectional_iterator_tag();
    }

    PUGI__FN std::bidirectional_iterator_tag __iterator_category(const pugi::xml_attribute_iterator&)
    {
        return std::bidirectional_iterator_tag();
    }

    PUGI__FN std::bidirectional_iterator_tag __iterator_category(const pugi::xml_named_node_iterator&)
    {
        return std::bidirectional_iterator_tag();
    }
}    // namespace std
#    endif

#    ifndef PUGIXML_NO_XPATH
// STL replacements
PUGI__NS_BEGIN
struct equal_to
{
    template<typename T>
    bool operator()(const T& lhs, const T& rhs) const
    {
        return lhs == rhs;
    }
};

struct not_equal_to
{
    template<typename T>
    bool operator()(const T& lhs, const T& rhs) const
    {
        return lhs != rhs;
    }
};

struct less
{
    template<typename T>
    bool operator()(const T& lhs, const T& rhs) const
    {
        return lhs < rhs;
    }
};

struct less_equal
{
    template<typename T>
    bool operator()(const T& lhs, const T& rhs) const
    {
        return lhs <= rhs;
    }
};

template<typename T>
inline void swap(T& lhs, T& rhs)
{
    T temp = lhs;
    lhs    = rhs;
    rhs    = temp;
}

template<typename I, typename Pred>
PUGI__FN I min_element(I begin, I end, const Pred& pred)
{
    I result = begin;

    for (I it = begin + 1; it != end; ++it)
        if (pred(*it, *result)) result = it;

    return result;
}

template<typename I>
PUGI__FN void reverse(I begin, I end)
{
    while (end - begin > 1) swap(*begin++, *--end);
}

template<typename I>
PUGI__FN I unique(I begin, I end)
{
    // fast skip head
    while (end - begin > 1 && *begin != *(begin + 1)) begin++;

    if (begin == end) return begin;

    // last written element
    I write = begin++;

    // merge unique elements
    while (begin != end) {
        if (*begin != *write)
            *++write = *begin++;
        else
            begin++;
    }

    // past-the-end (write points to live element)
    return write + 1;
}

template<typename T, typename Pred>
PUGI__FN void insertion_sort(T* begin, T* end, const Pred& pred)
{
    if (begin == end) return;

    for (T* it = begin + 1; it != end; ++it) {
        T  val  = *it;
        T* hole = it;

        // move hole backwards
        while (hole > begin && pred(val, *(hole - 1))) {
            *hole = *(hole - 1);
            hole--;
        }

        // fill hole with element
        *hole = val;
    }
}

template<typename I, typename Pred>
inline I median3(I first, I middle, I last, const Pred& pred)
{
    if (pred(*middle, *first)) swap(middle, first);
    if (pred(*last, *middle)) swap(last, middle);
    if (pred(*middle, *first)) swap(middle, first);

    return middle;
}

template<typename T, typename Pred>
PUGI__FN void partition3(T* begin, T* end, T pivot, const Pred& pred, T** out_eqbeg, T** out_eqend)
{
    // invariant: array is split into 4 groups: = < ? > (each variable denotes the boundary between the groups)
    T* eq = begin;
    T* lt = begin;
    T* gt = end;

    while (lt < gt) {
        if (pred(*lt, pivot))
            lt++;
        else if (*lt == pivot)
            swap(*eq++, *lt++);
        else
            swap(*lt, *--gt);
    }

    // we now have just 4 groups: = < >; move equal elements to the middle
    T* eqbeg = gt;

    for (T* it = begin; it != eq; ++it) swap(*it, *--eqbeg);

    *out_eqbeg = eqbeg;
    *out_eqend = gt;
}

template<typename I, typename Pred>
PUGI__FN void sort(I begin, I end, const Pred& pred)
{
    // sort large chunks
    while (end - begin > 16) {
        // find median element
        I middle = begin + (end - begin) / 2;
        I median = median3(begin, middle, end - 1, pred);

        // partition in three chunks (< = >)
        I eqbeg, eqend;
        partition3(begin, end, *median, pred, &eqbeg, &eqend);

        // loop on larger half
        if (eqbeg - begin > end - eqend) {
            sort(eqend, end, pred);
            end = eqbeg;
        }
        else {
            sort(begin, eqbeg, pred);
            begin = eqend;
        }
    }

    // insertion sort small chunk
    insertion_sort(begin, end, pred);
}

PUGI__FN bool hash_insert(const void** table, size_t size, const void* key)
{
    assert(key);

    unsigned int h = static_cast<unsigned int>(reinterpret_cast<uintptr_t>(key));

    // MurmurHash3 32-bit finalizer
    h ^= h >> 16;
    h *= 0x85ebca6bu;
    h ^= h >> 13;
    h *= 0xc2b2ae35u;
    h ^= h >> 16;

    size_t hashmod = size - 1;
    size_t bucket  = h & hashmod;

    for (size_t probe = 0; probe <= hashmod; ++probe) {
        if (table[bucket] == 0) {
            table[bucket] = key;
            return true;
        }

        if (table[bucket] == key) return false;

        // hash collision, quadratic probing
        bucket = (bucket + probe + 1) & hashmod;
    }

    assert(false && "Hash table is full");    // unreachable
    return false;
}
PUGI__NS_END

// Allocator used for AST and evaluation stacks
PUGI__NS_BEGIN
static const size_t xpath_memory_page_size =
#        ifdef PUGIXML_MEMORY_XPATH_PAGE_SIZE
    PUGIXML_MEMORY_XPATH_PAGE_SIZE
#        else
    4096
#        endif
    ;

static const uintptr_t xpath_memory_block_alignment = sizeof(double) > sizeof(void*) ? sizeof(double) : sizeof(void*);

struct xpath_memory_block
{
    xpath_memory_block* next;
    size_t              capacity;

    union
    {
        char   data[xpath_memory_page_size];
        double alignment;
    };
};

struct xpath_allocator
{
    xpath_memory_block* _root;
    size_t              _root_size;
    bool*               _error;

    xpath_allocator(xpath_memory_block* root, bool* error = 0) : _root(root), _root_size(0), _error(error) {}

    void* allocate(size_t size)
    {
        // round size up to block alignment boundary
        size = (size + xpath_memory_block_alignment - 1) & ~(xpath_memory_block_alignment - 1);

        if (_root_size + size <= _root->capacity) {
            void* buf = &_root->data[0] + _root_size;
            _root_size += size;
            return buf;
        }
        else {
            // make sure we have at least 1/4th of the page free after allocation to satisfy subsequent allocation requests
            size_t block_capacity_base = sizeof(_root->data);
            size_t block_capacity_req  = size + block_capacity_base / 4;
            size_t block_capacity      = (block_capacity_base > block_capacity_req) ? block_capacity_base : block_capacity_req;

            size_t block_size = block_capacity + offsetof(xpath_memory_block, data);

            xpath_memory_block* block = static_cast<xpath_memory_block*>(xml_memory::allocate(block_size));
            if (!block) {
                if (_error) *_error = true;
                return 0;
            }

            block->next     = _root;
            block->capacity = block_capacity;

            _root      = block;
            _root_size = size;

            return block->data;
        }
    }

    void* reallocate(void* ptr, size_t old_size, size_t new_size)
    {
        // round size up to block alignment boundary
        old_size = (old_size + xpath_memory_block_alignment - 1) & ~(xpath_memory_block_alignment - 1);
        new_size = (new_size + xpath_memory_block_alignment - 1) & ~(xpath_memory_block_alignment - 1);

        // we can only reallocate the last object
        assert(ptr == 0 || static_cast<char*>(ptr) + old_size == &_root->data[0] + _root_size);

        // try to reallocate the object inplace
        if (ptr && _root_size - old_size + new_size <= _root->capacity) {
            _root_size = _root_size - old_size + new_size;
            return ptr;
        }

        // allocate a new block
        void* result = allocate(new_size);
        if (!result) return 0;

        // we have a new block
        if (ptr) {
            // copy old data (we only support growing)
            assert(new_size >= old_size);
            memcpy(result, ptr, old_size);

            // free the previous page if it had no other objects
            assert(_root->data == result);
            assert(_root->next);

            if (_root->next->data == ptr) {
                // deallocate the whole page, unless it was the first one
                xpath_memory_block* next = _root->next->next;

                if (next) {
                    xml_memory::deallocate(_root->next);
                    _root->next = next;
                }
            }
        }

        return result;
    }

    void revert(const xpath_allocator& state)
    {
        // free all new pages
        xpath_memory_block* cur = _root;

        while (cur != state._root) {
            xpath_memory_block* next = cur->next;

            xml_memory::deallocate(cur);

            cur = next;
        }

        // restore state
        _root      = state._root;
        _root_size = state._root_size;
    }

    void release()
    {
        xpath_memory_block* cur = _root;
        assert(cur);

        while (cur->next) {
            xpath_memory_block* next = cur->next;

            xml_memory::deallocate(cur);

            cur = next;
        }
    }
};

struct xpath_allocator_capture
{
    xpath_allocator_capture(xpath_allocator* alloc) : _target(alloc), _state(*alloc) {}

    ~xpath_allocator_capture()
    {
        _target->revert(_state);
    }

    xpath_allocator* _target;
    xpath_allocator  _state;
};

struct xpath_stack
{
    xpath_allocator* result;
    xpath_allocator* temp;
};

struct xpath_stack_data
{
    xpath_memory_block blocks[2];
    xpath_allocator    result;
    xpath_allocator    temp;
    xpath_stack        stack;
    bool               oom;

    xpath_stack_data() : result(blocks + 0, &oom), temp(blocks + 1, &oom), oom(false)
    {
        blocks[0].next = blocks[1].next = 0;
        blocks[0].capacity = blocks[1].capacity = sizeof(blocks[0].data);

        stack.result = &result;
        stack.temp   = &temp;
    }

    ~xpath_stack_data()
    {
        result.release();
        temp.release();
    }
};
PUGI__NS_END

// String class
PUGI__NS_BEGIN
class xpath_string
{
    const char_t* _buffer;
    bool          _uses_heap;
    size_t        _length_heap;

    static char_t* duplicate_string(const char_t* string, size_t length, xpath_allocator* alloc)
    {
        char_t* result = static_cast<char_t*>(alloc->allocate((length + 1) * sizeof(char_t)));
        if (!result) return 0;

        memcpy(result, string, length * sizeof(char_t));
        result[length] = 0;

        return result;
    }

    xpath_string(const char_t* buffer, bool uses_heap_, size_t length_heap)
        : _buffer(buffer),
          _uses_heap(uses_heap_),
          _length_heap(length_heap)
    {}

public:
    static xpath_string from_const(const char_t* str)
    {
        return xpath_string(str, false, 0);
    }

    static xpath_string from_heap_preallocated(const char_t* begin, const char_t* end)
    {
        assert(begin <= end && *end == 0);

        return xpath_string(begin, true, static_cast<size_t>(end - begin));
    }

    static xpath_string from_heap(const char_t* begin, const char_t* end, xpath_allocator* alloc)
    {
        assert(begin <= end);

        if (begin == end) return xpath_string();

        size_t        length = static_cast<size_t>(end - begin);
        const char_t* data   = duplicate_string(begin, length, alloc);

        return data ? xpath_string(data, true, length) : xpath_string();
    }

    xpath_string() : _buffer(PUGIXML_TEXT("")), _uses_heap(false), _length_heap(0) {}

    void append(const xpath_string& o, xpath_allocator* alloc)
    {
        // skip empty sources
        if (!*o._buffer) return;

        // fast append for constant empty target and constant source
        if (!*_buffer && !_uses_heap && !o._uses_heap) {
            _buffer = o._buffer;
        }
        else {
            // need to make heap copy
            size_t target_length = length();
            size_t source_length = o.length();
            size_t result_length = target_length + source_length;

            // allocate new buffer
            char_t* result = static_cast<char_t*>(alloc->reallocate(_uses_heap ? const_cast<char_t*>(_buffer) : 0,
                                                                    (target_length + 1) * sizeof(char_t),
                                                                    (result_length + 1) * sizeof(char_t)));
            if (!result) return;

            // append first string to the new buffer in case there was no reallocation
            if (!_uses_heap) memcpy(result, _buffer, target_length * sizeof(char_t));

            // append second string to the new buffer
            memcpy(result + target_length, o._buffer, source_length * sizeof(char_t));
            result[result_length] = 0;

            // finalize
            _buffer      = result;
            _uses_heap   = true;
            _length_heap = result_length;
        }
    }

    const char_t* c_str() const
    {
        return _buffer;
    }

    size_t length() const
    {
        return _uses_heap ? _length_heap : strlength(_buffer);
    }

    char_t* data(xpath_allocator* alloc)
    {
        // make private heap copy
        if (!_uses_heap) {
            size_t        length_ = strlength(_buffer);
            const char_t* data_   = duplicate_string(_buffer, length_, alloc);

            if (!data_) return 0;

            _buffer      = data_;
            _uses_heap   = true;
            _length_heap = length_;
        }

        return const_cast<char_t*>(_buffer);
    }

    bool empty() const
    {
        return *_buffer == 0;
    }

    bool operator==(const xpath_string& o) const
    {
        return strequal(_buffer, o._buffer);
    }

    bool operator!=(const xpath_string& o) const
    {
        return !strequal(_buffer, o._buffer);
    }

    bool uses_heap() const
    {
        return _uses_heap;
    }
};
PUGI__NS_END

PUGI__NS_BEGIN
PUGI__FN bool starts_with(const char_t* string, const char_t* pattern)
{
    while (*pattern && *string == *pattern) {
        string++;
        pattern++;
    }

    return *pattern == 0;
}

PUGI__FN const char_t* find_char(const char_t* s, char_t c)
{
#        ifdef PUGIXML_WCHAR_MODE
    return wcschr(s, c);
#        else
    return strchr(s, c);
#        endif
}

PUGI__FN const char_t* find_substring(const char_t* s, const char_t* p)
{
#        ifdef PUGIXML_WCHAR_MODE
    // MSVC6 wcsstr bug workaround (if s is empty it always returns 0)
    return (*p == 0) ? s : wcsstr(s, p);
#        else
    return strstr(s, p);
#        endif
}

// Converts symbol to lower case, if it is an ASCII one
PUGI__FN char_t tolower_ascii(char_t ch)
{
    return static_cast<unsigned int>(ch - 'A') < 26 ? static_cast<char_t>(ch | ' ') : ch;
}

PUGI__FN xpath_string string_value(const xpath_node& na, xpath_allocator* alloc)
{
    if (na.attribute())
        return xpath_string::from_const(na.attribute().value());
    else {
        xml_node n = na.node();

        switch (n.type()) {
            case node_pcdata:
            case node_cdata:
            case node_comment:
            case node_pi:
                return xpath_string::from_const(n.value());

            case node_document:
            case node_element: {
                xpath_string result;

                // element nodes can have value if parse_embed_pcdata was used
                if (n.value()[0]) result.append(xpath_string::from_const(n.value()), alloc);

                xml_node cur = n.first_child();

                while (cur && cur != n) {
                    if (cur.type() == node_pcdata || cur.type() == node_cdata) result.append(xpath_string::from_const(cur.value()), alloc);

                    if (cur.first_child())
                        cur = cur.first_child();
                    else if (cur.next_sibling())
                        cur = cur.next_sibling();
                    else {
                        while (!cur.next_sibling() && cur != n) cur = cur.parent();

                        if (cur != n) cur = cur.next_sibling();
                    }
                }

                return result;
            }

            default:
                return xpath_string();
        }
    }
}

PUGI__FN bool node_is_before_sibling(xml_node_struct* ln, xml_node_struct* rn)
{
    assert(ln->parent == rn->parent);

    // there is no common ancestor (the shared parent is null), nodes are from different documents
    if (!ln->parent) return ln < rn;

    // determine sibling order
    xml_node_struct* ls = ln;
    xml_node_struct* rs = rn;

    while (ls && rs) {
        if (ls == rn) return true;
        if (rs == ln) return false;

        ls = ls->next_sibling;
        rs = rs->next_sibling;
    }

    // if rn sibling chain ended ln must be before rn
    return !rs;
}

PUGI__FN bool node_is_before(xml_node_struct* ln, xml_node_struct* rn)
{
    // find common ancestor at the same depth, if any
    xml_node_struct* lp = ln;
    xml_node_struct* rp = rn;

    while (lp && rp && lp->parent != rp->parent) {
        lp = lp->parent;
        rp = rp->parent;
    }

    // parents are the same!
    if (lp && rp) return node_is_before_sibling(lp, rp);

    // nodes are at different depths, need to normalize heights
    bool left_higher = !lp;

    while (lp) {
        lp = lp->parent;
        ln = ln->parent;
    }

    while (rp) {
        rp = rp->parent;
        rn = rn->parent;
    }

    // one node is the ancestor of the other
    if (ln == rn) return left_higher;

    // find common ancestor... again
    while (ln->parent != rn->parent) {
        ln = ln->parent;
        rn = rn->parent;
    }

    return node_is_before_sibling(ln, rn);
}

PUGI__FN bool node_is_ancestor(xml_node_struct* parent, xml_node_struct* node)
{
    while (node && node != parent) node = node->parent;

    return parent && node == parent;
}

PUGI__FN const void* document_buffer_order(const xpath_node& xnode)
{
    xml_node_struct* node = xnode.node().internal_object();

    if (node) {
        if ((get_document(node).header & xml_memory_page_contents_shared_mask) == 0) {
            if (node->name && (node->header & impl::xml_memory_page_name_allocated_or_shared_mask) == 0) return node->name;
            if (node->value && (node->header & impl::xml_memory_page_value_allocated_or_shared_mask) == 0) return node->value;
        }

        return 0;
    }

    xml_attribute_struct* attr = xnode.attribute().internal_object();

    if (attr) {
        if ((get_document(attr).header & xml_memory_page_contents_shared_mask) == 0) {
            if ((attr->header & impl::xml_memory_page_name_allocated_or_shared_mask) == 0) return attr->name;
            if ((attr->header & impl::xml_memory_page_value_allocated_or_shared_mask) == 0) return attr->value;
        }

        return 0;
    }

    return 0;
}

struct document_order_comparator
{
    bool operator()(const xpath_node& lhs, const xpath_node& rhs) const
    {
        // optimized document order based check
        const void* lo = document_buffer_order(lhs);
        const void* ro = document_buffer_order(rhs);

        if (lo && ro) return lo < ro;

        // slow comparison
        xml_node ln = lhs.node(), rn = rhs.node();

        // compare attributes
        if (lhs.attribute() && rhs.attribute()) {
            // shared parent
            if (lhs.parent() == rhs.parent()) {
                // determine sibling order
                for (xml_attribute a = lhs.attribute(); a; a = a.next_attribute())
                    if (a == rhs.attribute()) return true;

                return false;
            }

            // compare attribute parents
            ln = lhs.parent();
            rn = rhs.parent();
        }
        else if (lhs.attribute()) {
            // attributes go after the parent element
            if (lhs.parent() == rhs.node()) return false;

            ln = lhs.parent();
        }
        else if (rhs.attribute()) {
            // attributes go after the parent element
            if (rhs.parent() == lhs.node()) return true;

            rn = rhs.parent();
        }

        if (ln == rn) return false;

        if (!ln || !rn) return ln < rn;

        return node_is_before(ln.internal_object(), rn.internal_object());
    }
};

PUGI__FN double gen_nan()
{
#        if defined(__STDC_IEC_559__) || ((FLT_RADIX - 0 == 2) && (FLT_MAX_EXP - 0 == 128) && (FLT_MANT_DIG - 0 == 24))
    PUGI__STATIC_ASSERT(sizeof(float) == sizeof(uint32_t));
    typedef uint32_t UI;    // BCC5 workaround
    union
    {
        float f;
        UI    i;
    } u;
    u.i = 0x7fc00000;
    return double(u.f);
#        else
    // fallback
    const volatile double zero = 0.0;
    return zero / zero;
#        endif
}

PUGI__FN bool is_nan(double value)
{
#        if defined(PUGI__MSVC_CRT_VERSION) || defined(__BORLANDC__)
    return !!_isnan(value);
#        elif defined(fpclassify) && defined(FP_NAN)
    return fpclassify(value) == FP_NAN;
#        else
    // fallback
    const volatile double v = value;
    return v != v;
#        endif
}

PUGI__FN const char_t* convert_number_to_string_special(double value)
{
#        if defined(PUGI__MSVC_CRT_VERSION) || defined(__BORLANDC__)
    if (_finite(value)) return (value == 0) ? PUGIXML_TEXT("0") : 0;
    if (_isnan(value)) return PUGIXML_TEXT("NaN");
    return value > 0 ? PUGIXML_TEXT("Infinity") : PUGIXML_TEXT("-Infinity");
#        elif defined(fpclassify) && defined(FP_NAN) && defined(FP_INFINITE) && defined(FP_ZERO)
    switch (fpclassify(value)) {
        case FP_NAN:
            return PUGIXML_TEXT("NaN");

        case FP_INFINITE:
            return value > 0 ? PUGIXML_TEXT("Infinity") : PUGIXML_TEXT("-Infinity");

        case FP_ZERO:
            return PUGIXML_TEXT("0");

        default:
            return 0;
    }
#        else
    // fallback
    const volatile double v = value;

    if (v == 0) return PUGIXML_TEXT("0");
    if (v != v) return PUGIXML_TEXT("NaN");
    if (v * 2 == v) return value > 0 ? PUGIXML_TEXT("Infinity") : PUGIXML_TEXT("-Infinity");
    return 0;
#        endif
}

PUGI__FN bool convert_number_to_boolean(double value)
{
    return (value != 0 && !is_nan(value));
}

PUGI__FN void truncate_zeros(char* begin, char* end)
{
    while (begin != end && end[-1] == '0') end--;

    *end = 0;
}

// gets mantissa digits in the form of 0.xxxxx with 0. implied and the exponent
#        if defined(PUGI__MSVC_CRT_VERSION) && PUGI__MSVC_CRT_VERSION >= 1400 && !defined(_WIN32_WCE)
PUGI__FN void convert_number_to_mantissa_exponent(double value, char (&buffer)[32], char** out_mantissa, int* out_exponent)
{
    // get base values
    int sign, exponent;
    _ecvt_s(buffer, sizeof(buffer), value, DBL_DIG + 1, &exponent, &sign);

    // truncate redundant zeros
    truncate_zeros(buffer, buffer + strlen(buffer));

    // fill results
    *out_mantissa = buffer;
    *out_exponent = exponent;
}
#        else
PUGI__FN void convert_number_to_mantissa_exponent(double value, char (&buffer)[32], char** out_mantissa, int* out_exponent)
{
    // get a scientific notation value with IEEE DBL_DIG decimals
    PUGI__SNPRINTF(buffer, "%.*e", DBL_DIG, value);

    // get the exponent (possibly negative)
    char* exponent_string = strchr(buffer, 'e');
    assert(exponent_string);

    int exponent = atoi(exponent_string + 1);

    // extract mantissa string: skip sign
    char* mantissa = buffer[0] == '-' ? buffer + 1 : buffer;
    assert(mantissa[0] != '0' && mantissa[1] == '.');

    // divide mantissa by 10 to eliminate integer part
    mantissa[1] = mantissa[0];
    mantissa++;
    exponent++;

    // remove extra mantissa digits and zero-terminate mantissa
    truncate_zeros(mantissa, exponent_string);

    // fill results
    *out_mantissa = mantissa;
    *out_exponent = exponent;
}
#        endif

PUGI__FN xpath_string convert_number_to_string(double value, xpath_allocator* alloc)
{
    // try special number conversion
    const char_t* special = convert_number_to_string_special(value);
    if (special) return xpath_string::from_const(special);

    // get mantissa + exponent form
    char mantissa_buffer[32];

    char* mantissa;
    int   exponent;
    convert_number_to_mantissa_exponent(value, mantissa_buffer, &mantissa, &exponent);

    // allocate a buffer of suitable length for the number
    size_t  result_size = strlen(mantissa_buffer) + (exponent > 0 ? exponent : -exponent) + 4;
    char_t* result      = static_cast<char_t*>(alloc->allocate(sizeof(char_t) * result_size));
    if (!result) return xpath_string();

    // make the number!
    char_t* s = result;

    // sign
    if (value < 0) *s++ = '-';

    // integer part
    if (exponent <= 0) {
        *s++ = '0';
    }
    else {
        while (exponent > 0) {
            assert(*mantissa == 0 || static_cast<unsigned int>(*mantissa - '0') <= 9);
            *s++ = *mantissa ? *mantissa++ : '0';
            exponent--;
        }
    }

    // fractional part
    if (*mantissa) {
        // decimal point
        *s++ = '.';

        // extra zeroes from negative exponent
        while (exponent < 0) {
            *s++ = '0';
            exponent++;
        }

        // extra mantissa digits
        while (*mantissa) {
            assert(static_cast<unsigned int>(*mantissa - '0') <= 9);
            *s++ = *mantissa++;
        }
    }

    // zero-terminate
    assert(s < result + result_size);
    *s = 0;

    return xpath_string::from_heap_preallocated(result, s);
}

PUGI__FN bool check_string_to_number_format(const char_t* string)
{
    // parse leading whitespace
    while (PUGI__IS_CHARTYPE(*string, ct_space)) ++string;

    // parse sign
    if (*string == '-') ++string;

    if (!*string) return false;

    // if there is no integer part, there should be a decimal part with at least one digit
    if (!PUGI__IS_CHARTYPEX(string[0], ctx_digit) && (string[0] != '.' || !PUGI__IS_CHARTYPEX(string[1], ctx_digit))) return false;

    // parse integer part
    while (PUGI__IS_CHARTYPEX(*string, ctx_digit)) ++string;

    // parse decimal part
    if (*string == '.') {
        ++string;

        while (PUGI__IS_CHARTYPEX(*string, ctx_digit)) ++string;
    }

    // parse trailing whitespace
    while (PUGI__IS_CHARTYPE(*string, ct_space)) ++string;

    return *string == 0;
}

PUGI__FN double convert_string_to_number(const char_t* string)
{
    // check string format
    if (!check_string_to_number_format(string)) return gen_nan();

        // parse string
#        ifdef PUGIXML_WCHAR_MODE
    return wcstod(string, 0);
#        else
    return strtod(string, 0);
#        endif
}

PUGI__FN bool convert_string_to_number_scratch(char_t (&buffer)[32], const char_t* begin, const char_t* end, double* out_result)
{
    size_t  length  = static_cast<size_t>(end - begin);
    char_t* scratch = buffer;

    if (length >= sizeof(buffer) / sizeof(buffer[0])) {
        // need to make dummy on-heap copy
        scratch = static_cast<char_t*>(xml_memory::allocate((length + 1) * sizeof(char_t)));
        if (!scratch) return false;
    }

    // copy string to zero-terminated buffer and perform conversion
    memcpy(scratch, begin, length * sizeof(char_t));
    scratch[length] = 0;

    *out_result = convert_string_to_number(scratch);

    // free dummy buffer
    if (scratch != buffer) xml_memory::deallocate(scratch);

    return true;
}

PUGI__FN double round_nearest(double value)
{
    return floor(value + 0.5);
}

PUGI__FN double round_nearest_nzero(double value)
{
    // same as round_nearest, but returns -0 for [-0.5, -0]
    // ceil is used to differentiate between +0 and -0 (we return -0 for [-0.5, -0] and +0 for +0)
    return (value >= -0.5 && value <= 0) ? ceil(value) : floor(value + 0.5);
}

PUGI__FN const char_t* qualified_name(const xpath_node& node)
{
    return node.attribute() ? node.attribute().name() : node.node().name();
}

PUGI__FN const char_t* local_name(const xpath_node& node)
{
    const char_t* name = qualified_name(node);
    const char_t* p    = find_char(name, ':');

    return p ? p + 1 : name;
}

struct namespace_uri_predicate
{
    const char_t* prefix;
    size_t        prefix_length;

    namespace_uri_predicate(const char_t* name)
    {
        const char_t* pos = find_char(name, ':');

        prefix        = pos ? name : 0;
        prefix_length = pos ? static_cast<size_t>(pos - name) : 0;
    }

    bool operator()(xml_attribute a) const
    {
        const char_t* name = a.name();

        if (!starts_with(name, PUGIXML_TEXT("xmlns"))) return false;

        return prefix ? name[5] == ':' && strequalrange(name + 6, prefix, prefix_length) : name[5] == 0;
    }
};

PUGI__FN const char_t* namespace_uri(xml_node node)
{
    namespace_uri_predicate pred = node.name();

    xml_node p = node;

    while (p) {
        xml_attribute a = p.find_attribute(pred);

        if (a) return a.value();

        p = p.parent();
    }

    return PUGIXML_TEXT("");
}

PUGI__FN const char_t* namespace_uri(xml_attribute attr, xml_node parent)
{
    namespace_uri_predicate pred = attr.name();

    // Default namespace does not apply to attributes
    if (!pred.prefix) return PUGIXML_TEXT("");

    xml_node p = parent;

    while (p) {
        xml_attribute a = p.find_attribute(pred);

        if (a) return a.value();

        p = p.parent();
    }

    return PUGIXML_TEXT("");
}

PUGI__FN const char_t* namespace_uri(const xpath_node& node)
{
    return node.attribute() ? namespace_uri(node.attribute(), node.parent()) : namespace_uri(node.node());
}

PUGI__FN char_t* normalize_space(char_t* buffer)
{
    char_t* write = buffer;

    for (char_t* it = buffer; *it;) {
        char_t ch = *it++;

        if (PUGI__IS_CHARTYPE(ch, ct_space)) {
            // replace whitespace sequence with single space
            while (PUGI__IS_CHARTYPE(*it, ct_space)) it++;

            // avoid leading spaces
            if (write != buffer) *write++ = ' ';
        }
        else
            *write++ = ch;
    }

    // remove trailing space
    if (write != buffer && PUGI__IS_CHARTYPE(write[-1], ct_space)) write--;

    // zero-terminate
    *write = 0;

    return write;
}

PUGI__FN char_t* translate(char_t* buffer, const char_t* from, const char_t* to, size_t to_length)
{
    char_t* write = buffer;

    while (*buffer) {
        PUGI__DMC_VOLATILE char_t ch = *buffer++;

        const char_t* pos = find_char(from, ch);

        if (!pos)
            *write++ = ch;    // do not process
        else if (static_cast<size_t>(pos - from) < to_length)
            *write++ = to[pos - from];    // replace
    }

    // zero-terminate
    *write = 0;

    return write;
}

PUGI__FN unsigned char* translate_table_generate(xpath_allocator* alloc, const char_t* from, const char_t* to)
{
    unsigned char table[128] = { 0 };

    while (*from) {
        unsigned int fc = static_cast<unsigned int>(*from);
        unsigned int tc = static_cast<unsigned int>(*to);

        if (fc >= 128 || tc >= 128) return 0;

        // code=128 means "skip character"
        if (!table[fc]) table[fc] = static_cast<unsigned char>(tc ? tc : 128);

        from++;
        if (tc) to++;
    }

    for (int i = 0; i < 128; ++i)
        if (!table[i]) table[i] = static_cast<unsigned char>(i);

    void* result = alloc->allocate(sizeof(table));
    if (!result) return 0;

    memcpy(result, table, sizeof(table));

    return static_cast<unsigned char*>(result);
}

PUGI__FN char_t* translate_table(char_t* buffer, const unsigned char* table)
{
    char_t* write = buffer;

    while (*buffer) {
        char_t       ch    = *buffer++;
        unsigned int index = static_cast<unsigned int>(ch);

        if (index < 128) {
            unsigned char code = table[index];

            // code=128 means "skip character" (table size is 128 so 128 can be a special value)
            // this code skips these characters without extra branches
            *write = static_cast<char_t>(code);
            write += 1 - (code >> 7);
        }
        else {
            *write++ = ch;
        }
    }

    // zero-terminate
    *write = 0;

    return write;
}

inline bool is_xpath_attribute(const char_t* name)
{
    return !(starts_with(name, PUGIXML_TEXT("xmlns")) && (name[5] == 0 || name[5] == ':'));
}

struct xpath_variable_boolean : xpath_variable
{
    xpath_variable_boolean() : xpath_variable(xpath_type_boolean), value(false) {}

    bool   value;
    char_t name[1];
};

struct xpath_variable_number : xpath_variable
{
    xpath_variable_number() : xpath_variable(xpath_type_number), value(0) {}

    double value;
    char_t name[1];
};

struct xpath_variable_string : xpath_variable
{
    xpath_variable_string() : xpath_variable(xpath_type_string), value(0) {}

    ~xpath_variable_string()
    {
        if (value) xml_memory::deallocate(value);
    }

    char_t* value;
    char_t  name[1];
};

struct xpath_variable_node_set : xpath_variable
{
    xpath_variable_node_set() : xpath_variable(xpath_type_node_set) {}

    xpath_node_set value;
    char_t         name[1];
};

static const xpath_node_set dummy_node_set;

PUGI__FN PUGI__UNSIGNED_OVERFLOW unsigned int hash_string(const char_t* str)
{
    // Jenkins one-at-a-time hash (http://en.wikipedia.org/wiki/Jenkins_hash_function#one-at-a-time)
    unsigned int result = 0;

    while (*str) {
        result += static_cast<unsigned int>(*str++);
        result += result << 10;
        result ^= result >> 6;
    }

    result += result << 3;
    result ^= result >> 11;
    result += result << 15;

    return result;
}

template<typename T>
PUGI__FN T* new_xpath_variable(const char_t* name)
{
    size_t length = strlength(name);
    if (length == 0) return 0;    // empty variable names are invalid

    // $$ we can't use offsetof(T, name) because T is non-POD, so we just allocate additional length characters
    void* memory = xml_memory::allocate(sizeof(T) + length * sizeof(char_t));
    if (!memory) return 0;

    T* result = new (memory) T();

    memcpy(result->name, name, (length + 1) * sizeof(char_t));

    return result;
}

PUGI__FN xpath_variable* new_xpath_variable(xpath_value_type type, const char_t* name)
{
    switch (type) {
        case xpath_type_node_set:
            return new_xpath_variable<xpath_variable_node_set>(name);

        case xpath_type_number:
            return new_xpath_variable<xpath_variable_number>(name);

        case xpath_type_string:
            return new_xpath_variable<xpath_variable_string>(name);

        case xpath_type_boolean:
            return new_xpath_variable<xpath_variable_boolean>(name);

        default:
            return 0;
    }
}

template<typename T>
PUGI__FN void delete_xpath_variable(T* var)
{
    var->~T();
    xml_memory::deallocate(var);
}

PUGI__FN void delete_xpath_variable(xpath_value_type type, xpath_variable* var)
{
    switch (type) {
        case xpath_type_node_set:
            delete_xpath_variable(static_cast<xpath_variable_node_set*>(var));
            break;

        case xpath_type_number:
            delete_xpath_variable(static_cast<xpath_variable_number*>(var));
            break;

        case xpath_type_string:
            delete_xpath_variable(static_cast<xpath_variable_string*>(var));
            break;

        case xpath_type_boolean:
            delete_xpath_variable(static_cast<xpath_variable_boolean*>(var));
            break;

        default:
            assert(false && "Invalid variable type");    // unreachable
    }
}

PUGI__FN bool copy_xpath_variable(xpath_variable* lhs, const xpath_variable* rhs)
{
    switch (rhs->type()) {
        case xpath_type_node_set:
            return lhs->set(static_cast<const xpath_variable_node_set*>(rhs)->value);

        case xpath_type_number:
            return lhs->set(static_cast<const xpath_variable_number*>(rhs)->value);

        case xpath_type_string:
            return lhs->set(static_cast<const xpath_variable_string*>(rhs)->value);

        case xpath_type_boolean:
            return lhs->set(static_cast<const xpath_variable_boolean*>(rhs)->value);

        default:
            assert(false && "Invalid variable type");    // unreachable
            return false;
    }
}

PUGI__FN bool
    get_variable_scratch(char_t (&buffer)[32], xpath_variable_set* set, const char_t* begin, const char_t* end, xpath_variable** out_result)
{
    size_t  length  = static_cast<size_t>(end - begin);
    char_t* scratch = buffer;

    if (length >= sizeof(buffer) / sizeof(buffer[0])) {
        // need to make dummy on-heap copy
        scratch = static_cast<char_t*>(xml_memory::allocate((length + 1) * sizeof(char_t)));
        if (!scratch) return false;
    }

    // copy string to zero-terminated buffer and perform lookup
    memcpy(scratch, begin, length * sizeof(char_t));
    scratch[length] = 0;

    *out_result = set->get(scratch);

    // free dummy buffer
    if (scratch != buffer) xml_memory::deallocate(scratch);

    return true;
}
PUGI__NS_END

// Internal node set class
PUGI__NS_BEGIN
PUGI__FN xpath_node_set::type_t xpath_get_order(const xpath_node* begin, const xpath_node* end)
{
    if (end - begin < 2) return xpath_node_set::type_sorted;

    document_order_comparator cmp;

    bool first = cmp(begin[0], begin[1]);

    for (const xpath_node* it = begin + 1; it + 1 < end; ++it)
        if (cmp(it[0], it[1]) != first) return xpath_node_set::type_unsorted;

    return first ? xpath_node_set::type_sorted : xpath_node_set::type_sorted_reverse;
}

PUGI__FN xpath_node_set::type_t xpath_sort(xpath_node* begin, xpath_node* end, xpath_node_set::type_t type, bool rev)
{
    xpath_node_set::type_t order = rev ? xpath_node_set::type_sorted_reverse : xpath_node_set::type_sorted;

    if (type == xpath_node_set::type_unsorted) {
        xpath_node_set::type_t sorted = xpath_get_order(begin, end);

        if (sorted == xpath_node_set::type_unsorted) {
            sort(begin, end, document_order_comparator());

            type = xpath_node_set::type_sorted;
        }
        else
            type = sorted;
    }

    if (type != order) reverse(begin, end);

    return order;
}

PUGI__FN xpath_node xpath_first(const xpath_node* begin, const xpath_node* end, xpath_node_set::type_t type)
{
    if (begin == end) return xpath_node();

    switch (type) {
        case xpath_node_set::type_sorted:
            return *begin;

        case xpath_node_set::type_sorted_reverse:
            return *(end - 1);

        case xpath_node_set::type_unsorted:
            return *min_element(begin, end, document_order_comparator());

        default:
            assert(false && "Invalid node set type");    // unreachable
            return xpath_node();
    }
}

class xpath_node_set_raw
{
    xpath_node_set::type_t _type;

    xpath_node* _begin;
    xpath_node* _end;
    xpath_node* _eos;

public:
    xpath_node_set_raw() : _type(xpath_node_set::type_unsorted), _begin(0), _end(0), _eos(0) {}

    xpath_node* begin() const
    {
        return _begin;
    }

    xpath_node* end() const
    {
        return _end;
    }

    bool empty() const
    {
        return _begin == _end;
    }

    size_t size() const
    {
        return static_cast<size_t>(_end - _begin);
    }

    xpath_node first() const
    {
        return xpath_first(_begin, _end, _type);
    }

    void push_back_grow(const xpath_node& node, xpath_allocator* alloc);

    void push_back(const xpath_node& node, xpath_allocator* alloc)
    {
        if (_end != _eos)
            *_end++ = node;
        else
            push_back_grow(node, alloc);
    }

    void append(const xpath_node* begin_, const xpath_node* end_, xpath_allocator* alloc)
    {
        if (begin_ == end_) return;

        size_t size_    = static_cast<size_t>(_end - _begin);
        size_t capacity = static_cast<size_t>(_eos - _begin);
        size_t count    = static_cast<size_t>(end_ - begin_);

        if (size_ + count > capacity) {
            // reallocate the old array or allocate a new one
            xpath_node* data =
                static_cast<xpath_node*>(alloc->reallocate(_begin, capacity * sizeof(xpath_node), (size_ + count) * sizeof(xpath_node)));
            if (!data) return;

            // finalize
            _begin = data;
            _end   = data + size_;
            _eos   = data + size_ + count;
        }

        memcpy(_end, begin_, count * sizeof(xpath_node));
        _end += count;
    }

    void sort_do()
    {
        _type = xpath_sort(_begin, _end, _type, false);
    }

    void truncate(xpath_node* pos)
    {
        assert(_begin <= pos && pos <= _end);

        _end = pos;
    }

    void remove_duplicates(xpath_allocator* alloc)
    {
        if (_type == xpath_node_set::type_unsorted && _end - _begin > 2) {
            xpath_allocator_capture cr(alloc);

            size_t size_ = static_cast<size_t>(_end - _begin);

            size_t hash_size = 1;
            while (hash_size < size_ + size_ / 2) hash_size *= 2;

            const void** hash_data = static_cast<const void**>(alloc->allocate(hash_size * sizeof(void**)));
            if (!hash_data) return;

            memset(hash_data, 0, hash_size * sizeof(const void**));

            xpath_node* write = _begin;

            for (xpath_node* it = _begin; it != _end; ++it) {
                const void* attr = it->attribute().internal_object();
                const void* node = it->node().internal_object();
                const void* key  = attr ? attr : node;

                if (key && hash_insert(hash_data, hash_size, key)) {
                    *write++ = *it;
                }
            }

            _end = write;
        }
        else {
            _end = unique(_begin, _end);
        }
    }

    xpath_node_set::type_t type() const
    {
        return _type;
    }

    void set_type(xpath_node_set::type_t value)
    {
        _type = value;
    }
};

PUGI__FN_NO_INLINE void xpath_node_set_raw::push_back_grow(const xpath_node& node, xpath_allocator* alloc)
{
    size_t capacity = static_cast<size_t>(_eos - _begin);

    // get new capacity (1.5x rule)
    size_t new_capacity = capacity + capacity / 2 + 1;

    // reallocate the old array or allocate a new one
    xpath_node* data =
        static_cast<xpath_node*>(alloc->reallocate(_begin, capacity * sizeof(xpath_node), new_capacity * sizeof(xpath_node)));
    if (!data) return;

    // finalize
    _begin = data;
    _end   = data + capacity;
    _eos   = data + new_capacity;

    // push
    *_end++ = node;
}
PUGI__NS_END

PUGI__NS_BEGIN
struct xpath_context
{
    xpath_node n;
    size_t     position, size;

    xpath_context(const xpath_node& n_, size_t position_, size_t size_) : n(n_), position(position_), size(size_) {}
};

enum lexeme_t {
    lex_none = 0,
    lex_equal,
    lex_not_equal,
    lex_less,
    lex_greater,
    lex_less_or_equal,
    lex_greater_or_equal,
    lex_plus,
    lex_minus,
    lex_multiply,
    lex_union,
    lex_var_ref,
    lex_open_brace,
    lex_close_brace,
    lex_quoted_string,
    lex_number,
    lex_slash,
    lex_double_slash,
    lex_open_square_brace,
    lex_close_square_brace,
    lex_string,
    lex_comma,
    lex_axis_attribute,
    lex_dot,
    lex_double_dot,
    lex_double_colon,
    lex_eof
};

struct xpath_lexer_string
{
    const char_t* begin;
    const char_t* end;

    xpath_lexer_string() : begin(0), end(0) {}

    bool operator==(const char_t* other) const
    {
        size_t length = static_cast<size_t>(end - begin);

        return strequalrange(other, begin, length);
    }
};

class xpath_lexer
{
    const char_t*      _cur;
    const char_t*      _cur_lexeme_pos;
    xpath_lexer_string _cur_lexeme_contents;

    lexeme_t _cur_lexeme;

public:
    explicit xpath_lexer(const char_t* query) : _cur(query)
    {
        next();
    }

    const char_t* state() const
    {
        return _cur;
    }

    void next()
    {
        const char_t* cur = _cur;

        while (PUGI__IS_CHARTYPE(*cur, ct_space)) ++cur;

        // save lexeme position for error reporting
        _cur_lexeme_pos = cur;

        switch (*cur) {
            case 0:
                _cur_lexeme = lex_eof;
                break;

            case '>':
                if (*(cur + 1) == '=') {
                    cur += 2;
                    _cur_lexeme = lex_greater_or_equal;
                }
                else {
                    cur += 1;
                    _cur_lexeme = lex_greater;
                }
                break;

            case '<':
                if (*(cur + 1) == '=') {
                    cur += 2;
                    _cur_lexeme = lex_less_or_equal;
                }
                else {
                    cur += 1;
                    _cur_lexeme = lex_less;
                }
                break;

            case '!':
                if (*(cur + 1) == '=') {
                    cur += 2;
                    _cur_lexeme = lex_not_equal;
                }
                else {
                    _cur_lexeme = lex_none;
                }
                break;

            case '=':
                cur += 1;
                _cur_lexeme = lex_equal;

                break;

            case '+':
                cur += 1;
                _cur_lexeme = lex_plus;

                break;

            case '-':
                cur += 1;
                _cur_lexeme = lex_minus;

                break;

            case '*':
                cur += 1;
                _cur_lexeme = lex_multiply;

                break;

            case '|':
                cur += 1;
                _cur_lexeme = lex_union;

                break;

            case '$':
                cur += 1;

                if (PUGI__IS_CHARTYPEX(*cur, ctx_start_symbol)) {
                    _cur_lexeme_contents.begin = cur;

                    while (PUGI__IS_CHARTYPEX(*cur, ctx_symbol)) cur++;

                    if (cur[0] == ':' && PUGI__IS_CHARTYPEX(cur[1], ctx_symbol))    // qname
                    {
                        cur++;    // :

                        while (PUGI__IS_CHARTYPEX(*cur, ctx_symbol)) cur++;
                    }

                    _cur_lexeme_contents.end = cur;

                    _cur_lexeme = lex_var_ref;
                }
                else {
                    _cur_lexeme = lex_none;
                }

                break;

            case '(':
                cur += 1;
                _cur_lexeme = lex_open_brace;

                break;

            case ')':
                cur += 1;
                _cur_lexeme = lex_close_brace;

                break;

            case '[':
                cur += 1;
                _cur_lexeme = lex_open_square_brace;

                break;

            case ']':
                cur += 1;
                _cur_lexeme = lex_close_square_brace;

                break;

            case ',':
                cur += 1;
                _cur_lexeme = lex_comma;

                break;

            case '/':
                if (*(cur + 1) == '/') {
                    cur += 2;
                    _cur_lexeme = lex_double_slash;
                }
                else {
                    cur += 1;
                    _cur_lexeme = lex_slash;
                }
                break;

            case '.':
                if (*(cur + 1) == '.') {
                    cur += 2;
                    _cur_lexeme = lex_double_dot;
                }
                else if (PUGI__IS_CHARTYPEX(*(cur + 1), ctx_digit)) {
                    _cur_lexeme_contents.begin = cur;    // .

                    ++cur;

                    while (PUGI__IS_CHARTYPEX(*cur, ctx_digit)) cur++;

                    _cur_lexeme_contents.end = cur;

                    _cur_lexeme = lex_number;
                }
                else {
                    cur += 1;
                    _cur_lexeme = lex_dot;
                }
                break;

            case '@':
                cur += 1;
                _cur_lexeme = lex_axis_attribute;

                break;

            case '"':
            case '\'': {
                char_t terminator = *cur;

                ++cur;

                _cur_lexeme_contents.begin = cur;
                while (*cur && *cur != terminator) cur++;
                _cur_lexeme_contents.end = cur;

                if (!*cur)
                    _cur_lexeme = lex_none;
                else {
                    cur += 1;
                    _cur_lexeme = lex_quoted_string;
                }

                break;
            }

            case ':':
                if (*(cur + 1) == ':') {
                    cur += 2;
                    _cur_lexeme = lex_double_colon;
                }
                else {
                    _cur_lexeme = lex_none;
                }
                break;

            default:
                if (PUGI__IS_CHARTYPEX(*cur, ctx_digit)) {
                    _cur_lexeme_contents.begin = cur;

                    while (PUGI__IS_CHARTYPEX(*cur, ctx_digit)) cur++;

                    if (*cur == '.') {
                        cur++;

                        while (PUGI__IS_CHARTYPEX(*cur, ctx_digit)) cur++;
                    }

                    _cur_lexeme_contents.end = cur;

                    _cur_lexeme = lex_number;
                }
                else if (PUGI__IS_CHARTYPEX(*cur, ctx_start_symbol)) {
                    _cur_lexeme_contents.begin = cur;

                    while (PUGI__IS_CHARTYPEX(*cur, ctx_symbol)) cur++;

                    if (cur[0] == ':') {
                        if (cur[1] == '*')    // namespace test ncname:*
                        {
                            cur += 2;    // :*
                        }
                        else if (PUGI__IS_CHARTYPEX(cur[1], ctx_symbol))    // namespace test qname
                        {
                            cur++;    // :

                            while (PUGI__IS_CHARTYPEX(*cur, ctx_symbol)) cur++;
                        }
                    }

                    _cur_lexeme_contents.end = cur;

                    _cur_lexeme = lex_string;
                }
                else {
                    _cur_lexeme = lex_none;
                }
        }

        _cur = cur;
    }

    lexeme_t current() const
    {
        return _cur_lexeme;
    }

    const char_t* current_pos() const
    {
        return _cur_lexeme_pos;
    }

    const xpath_lexer_string& contents() const
    {
        assert(_cur_lexeme == lex_var_ref || _cur_lexeme == lex_number || _cur_lexeme == lex_string || _cur_lexeme == lex_quoted_string);

        return _cur_lexeme_contents;
    }
};

enum ast_type_t {
    ast_unknown,
    ast_op_or,                     // left or right
    ast_op_and,                    // left and right
    ast_op_equal,                  // left = right
    ast_op_not_equal,              // left != right
    ast_op_less,                   // left < right
    ast_op_greater,                // left > right
    ast_op_less_or_equal,          // left <= right
    ast_op_greater_or_equal,       // left >= right
    ast_op_add,                    // left + right
    ast_op_subtract,               // left - right
    ast_op_multiply,               // left * right
    ast_op_divide,                 // left / right
    ast_op_mod,                    // left % right
    ast_op_negate,                 // left - right
    ast_op_union,                  // left | right
    ast_predicate,                 // apply predicate to set; next points to next predicate
    ast_filter,                    // select * from left where right
    ast_string_constant,           // string constant
    ast_number_constant,           // number constant
    ast_variable,                  // variable
    ast_func_last,                 // last()
    ast_func_position,             // position()
    ast_func_count,                // count(left)
    ast_func_id,                   // id(left)
    ast_func_local_name_0,         // local-name()
    ast_func_local_name_1,         // local-name(left)
    ast_func_namespace_uri_0,      // namespace-uri()
    ast_func_namespace_uri_1,      // namespace-uri(left)
    ast_func_name_0,               // name()
    ast_func_name_1,               // name(left)
    ast_func_string_0,             // string()
    ast_func_string_1,             // string(left)
    ast_func_concat,               // concat(left, right, siblings)
    ast_func_starts_with,          // starts_with(left, right)
    ast_func_contains,             // contains(left, right)
    ast_func_substring_before,     // substring-before(left, right)
    ast_func_substring_after,      // substring-after(left, right)
    ast_func_substring_2,          // substring(left, right)
    ast_func_substring_3,          // substring(left, right, third)
    ast_func_string_length_0,      // string-length()
    ast_func_string_length_1,      // string-length(left)
    ast_func_normalize_space_0,    // normalize-space()
    ast_func_normalize_space_1,    // normalize-space(left)
    ast_func_translate,            // translate(left, right, third)
    ast_func_boolean,              // boolean(left)
    ast_func_not,                  // not(left)
    ast_func_true,                 // true()
    ast_func_false,                // false()
    ast_func_lang,                 // lang(left)
    ast_func_number_0,             // number()
    ast_func_number_1,             // number(left)
    ast_func_sum,                  // sum(left)
    ast_func_floor,                // floor(left)
    ast_func_ceiling,              // ceiling(left)
    ast_func_round,                // round(left)
    ast_step,                      // process set left with step
    ast_step_root,                 // select root node

    ast_opt_translate_table,     // translate(left, right, third) where right/third are constants
    ast_opt_compare_attribute    // @name = 'string'
};

enum axis_t {
    axis_ancestor,
    axis_ancestor_or_self,
    axis_attribute,
    axis_child,
    axis_descendant,
    axis_descendant_or_self,
    axis_following,
    axis_following_sibling,
    axis_namespace,
    axis_parent,
    axis_preceding,
    axis_preceding_sibling,
    axis_self
};

enum nodetest_t {
    nodetest_none,
    nodetest_name,
    nodetest_type_node,
    nodetest_type_comment,
    nodetest_type_pi,
    nodetest_type_text,
    nodetest_pi,
    nodetest_all,
    nodetest_all_in_namespace
};

enum predicate_t { predicate_default, predicate_posinv, predicate_constant, predicate_constant_one };

enum nodeset_eval_t { nodeset_eval_all, nodeset_eval_any, nodeset_eval_first };

template<axis_t N>
struct axis_to_type
{
    static const axis_t axis;
};

template<axis_t N>
const axis_t axis_to_type<N>::axis = N;

class xpath_ast_node
{
private:
    // node type
    char _type;
    char _rettype;

    // for ast_step
    char _axis;

    // for ast_step/ast_predicate/ast_filter
    char _test;

    // tree node structure
    xpath_ast_node* _left;
    xpath_ast_node* _right;
    xpath_ast_node* _next;

    union
    {
        // value for ast_string_constant
        const char_t* string;
        // value for ast_number_constant
        double number;
        // variable for ast_variable
        xpath_variable* variable;
        // node test for ast_step (node name/namespace/node type/pi target)
        const char_t* nodetest;
        // table for ast_opt_translate_table
        const unsigned char* table;
    } _data;

    xpath_ast_node(const xpath_ast_node&);
    xpath_ast_node& operator=(const xpath_ast_node&);

    template<class Comp>
    static bool compare_eq(xpath_ast_node* lhs, xpath_ast_node* rhs, const xpath_context& c, const xpath_stack& stack, const Comp& comp)
    {
        xpath_value_type lt = lhs->rettype(), rt = rhs->rettype();

        if (lt != xpath_type_node_set && rt != xpath_type_node_set) {
            if (lt == xpath_type_boolean || rt == xpath_type_boolean)
                return comp(lhs->eval_boolean(c, stack), rhs->eval_boolean(c, stack));
            else if (lt == xpath_type_number || rt == xpath_type_number)
                return comp(lhs->eval_number(c, stack), rhs->eval_number(c, stack));
            else if (lt == xpath_type_string || rt == xpath_type_string) {
                xpath_allocator_capture cr(stack.result);

                xpath_string ls = lhs->eval_string(c, stack);
                xpath_string rs = rhs->eval_string(c, stack);

                return comp(ls, rs);
            }
        }
        else if (lt == xpath_type_node_set && rt == xpath_type_node_set) {
            xpath_allocator_capture cr(stack.result);

            xpath_node_set_raw ls = lhs->eval_node_set(c, stack, nodeset_eval_all);
            xpath_node_set_raw rs = rhs->eval_node_set(c, stack, nodeset_eval_all);

            for (const xpath_node* li = ls.begin(); li != ls.end(); ++li)
                for (const xpath_node* ri = rs.begin(); ri != rs.end(); ++ri) {
                    xpath_allocator_capture cri(stack.result);

                    if (comp(string_value(*li, stack.result), string_value(*ri, stack.result))) return true;
                }

            return false;
        }
        else {
            if (lt == xpath_type_node_set) {
                swap(lhs, rhs);
                swap(lt, rt);
            }

            if (lt == xpath_type_boolean)
                return comp(lhs->eval_boolean(c, stack), rhs->eval_boolean(c, stack));
            else if (lt == xpath_type_number) {
                xpath_allocator_capture cr(stack.result);

                double             l  = lhs->eval_number(c, stack);
                xpath_node_set_raw rs = rhs->eval_node_set(c, stack, nodeset_eval_all);

                for (const xpath_node* ri = rs.begin(); ri != rs.end(); ++ri) {
                    xpath_allocator_capture cri(stack.result);

                    if (comp(l, convert_string_to_number(string_value(*ri, stack.result).c_str()))) return true;
                }

                return false;
            }
            else if (lt == xpath_type_string) {
                xpath_allocator_capture cr(stack.result);

                xpath_string       l  = lhs->eval_string(c, stack);
                xpath_node_set_raw rs = rhs->eval_node_set(c, stack, nodeset_eval_all);

                for (const xpath_node* ri = rs.begin(); ri != rs.end(); ++ri) {
                    xpath_allocator_capture cri(stack.result);

                    if (comp(l, string_value(*ri, stack.result))) return true;
                }

                return false;
            }
        }

        assert(false && "Wrong types");    // unreachable
        return false;
    }

    static bool eval_once(xpath_node_set::type_t type, nodeset_eval_t eval)
    {
        return type == xpath_node_set::type_sorted ? eval != nodeset_eval_all : eval == nodeset_eval_any;
    }

    template<class Comp>
    static bool compare_rel(xpath_ast_node* lhs, xpath_ast_node* rhs, const xpath_context& c, const xpath_stack& stack, const Comp& comp)
    {
        xpath_value_type lt = lhs->rettype(), rt = rhs->rettype();

        if (lt != xpath_type_node_set && rt != xpath_type_node_set)
            return comp(lhs->eval_number(c, stack), rhs->eval_number(c, stack));
        else if (lt == xpath_type_node_set && rt == xpath_type_node_set) {
            xpath_allocator_capture cr(stack.result);

            xpath_node_set_raw ls = lhs->eval_node_set(c, stack, nodeset_eval_all);
            xpath_node_set_raw rs = rhs->eval_node_set(c, stack, nodeset_eval_all);

            for (const xpath_node* li = ls.begin(); li != ls.end(); ++li) {
                xpath_allocator_capture cri(stack.result);

                double l = convert_string_to_number(string_value(*li, stack.result).c_str());

                for (const xpath_node* ri = rs.begin(); ri != rs.end(); ++ri) {
                    xpath_allocator_capture crii(stack.result);

                    if (comp(l, convert_string_to_number(string_value(*ri, stack.result).c_str()))) return true;
                }
            }

            return false;
        }
        else if (lt != xpath_type_node_set && rt == xpath_type_node_set) {
            xpath_allocator_capture cr(stack.result);

            double             l  = lhs->eval_number(c, stack);
            xpath_node_set_raw rs = rhs->eval_node_set(c, stack, nodeset_eval_all);

            for (const xpath_node* ri = rs.begin(); ri != rs.end(); ++ri) {
                xpath_allocator_capture cri(stack.result);

                if (comp(l, convert_string_to_number(string_value(*ri, stack.result).c_str()))) return true;
            }

            return false;
        }
        else if (lt == xpath_type_node_set && rt != xpath_type_node_set) {
            xpath_allocator_capture cr(stack.result);

            xpath_node_set_raw ls = lhs->eval_node_set(c, stack, nodeset_eval_all);
            double             r  = rhs->eval_number(c, stack);

            for (const xpath_node* li = ls.begin(); li != ls.end(); ++li) {
                xpath_allocator_capture cri(stack.result);

                if (comp(convert_string_to_number(string_value(*li, stack.result).c_str()), r)) return true;
            }

            return false;
        }
        else {
            assert(false && "Wrong types");    // unreachable
            return false;
        }
    }

    static void apply_predicate_boolean(xpath_node_set_raw& ns, size_t first, xpath_ast_node* expr, const xpath_stack& stack, bool once)
    {
        assert(ns.size() >= first);
        assert(expr->rettype() != xpath_type_number);

        size_t i    = 1;
        size_t size = ns.size() - first;

        xpath_node* last = ns.begin() + first;

        // remove_if... or well, sort of
        for (xpath_node* it = last; it != ns.end(); ++it, ++i) {
            xpath_context c(*it, i, size);

            if (expr->eval_boolean(c, stack)) {
                *last++ = *it;

                if (once) break;
            }
        }

        ns.truncate(last);
    }

    static void apply_predicate_number(xpath_node_set_raw& ns, size_t first, xpath_ast_node* expr, const xpath_stack& stack, bool once)
    {
        assert(ns.size() >= first);
        assert(expr->rettype() == xpath_type_number);

        size_t i    = 1;
        size_t size = ns.size() - first;

        xpath_node* last = ns.begin() + first;

        // remove_if... or well, sort of
        for (xpath_node* it = last; it != ns.end(); ++it, ++i) {
            xpath_context c(*it, i, size);

            if (expr->eval_number(c, stack) == i) {
                *last++ = *it;

                if (once) break;
            }
        }

        ns.truncate(last);
    }

    static void apply_predicate_number_const(xpath_node_set_raw& ns, size_t first, xpath_ast_node* expr, const xpath_stack& stack)
    {
        assert(ns.size() >= first);
        assert(expr->rettype() == xpath_type_number);

        size_t size = ns.size() - first;

        xpath_node* last = ns.begin() + first;

        xpath_context c(xpath_node(), 1, size);

        double er = expr->eval_number(c, stack);

        if (er >= 1.0 && er <= size) {
            size_t eri = static_cast<size_t>(er);

            if (er == eri) {
                xpath_node r = last[eri - 1];

                *last++ = r;
            }
        }

        ns.truncate(last);
    }

    void apply_predicate(xpath_node_set_raw& ns, size_t first, const xpath_stack& stack, bool once)
    {
        if (ns.size() == first) return;

        assert(_type == ast_filter || _type == ast_predicate);

        if (_test == predicate_constant || _test == predicate_constant_one)
            apply_predicate_number_const(ns, first, _right, stack);
        else if (_right->rettype() == xpath_type_number)
            apply_predicate_number(ns, first, _right, stack, once);
        else
            apply_predicate_boolean(ns, first, _right, stack, once);
    }

    void apply_predicates(xpath_node_set_raw& ns, size_t first, const xpath_stack& stack, nodeset_eval_t eval)
    {
        if (ns.size() == first) return;

        bool last_once = eval_once(ns.type(), eval);

        for (xpath_ast_node* pred = _right; pred; pred = pred->_next) pred->apply_predicate(ns, first, stack, !pred->_next && last_once);
    }

    bool step_push(xpath_node_set_raw& ns, xml_attribute_struct* a, xml_node_struct* parent, xpath_allocator* alloc)
    {
        assert(a);

        const char_t* name = a->name ? a->name + 0 : PUGIXML_TEXT("");

        switch (_test) {
            case nodetest_name:
                if (strequal(name, _data.nodetest) && is_xpath_attribute(name)) {
                    ns.push_back(xpath_node(xml_attribute(a), xml_node(parent)), alloc);
                    return true;
                }
                break;

            case nodetest_type_node:
            case nodetest_all:
                if (is_xpath_attribute(name)) {
                    ns.push_back(xpath_node(xml_attribute(a), xml_node(parent)), alloc);
                    return true;
                }
                break;

            case nodetest_all_in_namespace:
                if (starts_with(name, _data.nodetest) && is_xpath_attribute(name)) {
                    ns.push_back(xpath_node(xml_attribute(a), xml_node(parent)), alloc);
                    return true;
                }
                break;

            default:;
        }

        return false;
    }

    bool step_push(xpath_node_set_raw& ns, xml_node_struct* n, xpath_allocator* alloc)
    {
        assert(n);

        xml_node_type type = PUGI__NODETYPE(n);

        switch (_test) {
            case nodetest_name:
                if (type == node_element && n->name && strequal(n->name, _data.nodetest)) {
                    ns.push_back(xml_node(n), alloc);
                    return true;
                }
                break;

            case nodetest_type_node:
                ns.push_back(xml_node(n), alloc);
                return true;

            case nodetest_type_comment:
                if (type == node_comment) {
                    ns.push_back(xml_node(n), alloc);
                    return true;
                }
                break;

            case nodetest_type_text:
                if (type == node_pcdata || type == node_cdata) {
                    ns.push_back(xml_node(n), alloc);
                    return true;
                }
                break;

            case nodetest_type_pi:
                if (type == node_pi) {
                    ns.push_back(xml_node(n), alloc);
                    return true;
                }
                break;

            case nodetest_pi:
                if (type == node_pi && n->name && strequal(n->name, _data.nodetest)) {
                    ns.push_back(xml_node(n), alloc);
                    return true;
                }
                break;

            case nodetest_all:
                if (type == node_element) {
                    ns.push_back(xml_node(n), alloc);
                    return true;
                }
                break;

            case nodetest_all_in_namespace:
                if (type == node_element && n->name && starts_with(n->name, _data.nodetest)) {
                    ns.push_back(xml_node(n), alloc);
                    return true;
                }
                break;

            default:
                assert(false && "Unknown axis");    // unreachable
        }

        return false;
    }

    template<class T>
    void step_fill(xpath_node_set_raw& ns, xml_node_struct* n, xpath_allocator* alloc, bool once, T)
    {
        const axis_t axis = T::axis;

        switch (axis) {
            case axis_attribute: {
                for (xml_attribute_struct* a = n->first_attribute; a; a = a->next_attribute)
                    if (step_push(ns, a, n, alloc) & once) return;

                break;
            }

            case axis_child: {
                for (xml_node_struct* c = n->first_child; c; c = c->next_sibling)
                    if (step_push(ns, c, alloc) & once) return;

                break;
            }

            case axis_descendant:
            case axis_descendant_or_self: {
                if (axis == axis_descendant_or_self)
                    if (step_push(ns, n, alloc) & once) return;

                xml_node_struct* cur = n->first_child;

                while (cur) {
                    if (step_push(ns, cur, alloc) & once) return;

                    if (cur->first_child)
                        cur = cur->first_child;
                    else {
                        while (!cur->next_sibling) {
                            cur = cur->parent;

                            if (cur == n) return;
                        }

                        cur = cur->next_sibling;
                    }
                }

                break;
            }

            case axis_following_sibling: {
                for (xml_node_struct* c = n->next_sibling; c; c = c->next_sibling)
                    if (step_push(ns, c, alloc) & once) return;

                break;
            }

            case axis_preceding_sibling: {
                for (xml_node_struct* c = n->prev_sibling_c; c->next_sibling; c = c->prev_sibling_c)
                    if (step_push(ns, c, alloc) & once) return;

                break;
            }

            case axis_following: {
                xml_node_struct* cur = n;

                // exit from this node so that we don't include descendants
                while (!cur->next_sibling) {
                    cur = cur->parent;

                    if (!cur) return;
                }

                cur = cur->next_sibling;

                while (cur) {
                    if (step_push(ns, cur, alloc) & once) return;

                    if (cur->first_child)
                        cur = cur->first_child;
                    else {
                        while (!cur->next_sibling) {
                            cur = cur->parent;

                            if (!cur) return;
                        }

                        cur = cur->next_sibling;
                    }
                }

                break;
            }

            case axis_preceding: {
                xml_node_struct* cur = n;

                // exit from this node so that we don't include descendants
                while (!cur->prev_sibling_c->next_sibling) {
                    cur = cur->parent;

                    if (!cur) return;
                }

                cur = cur->prev_sibling_c;

                while (cur) {
                    if (cur->first_child)
                        cur = cur->first_child->prev_sibling_c;
                    else {
                        // leaf node, can't be ancestor
                        if (step_push(ns, cur, alloc) & once) return;

                        while (!cur->prev_sibling_c->next_sibling) {
                            cur = cur->parent;

                            if (!cur) return;

                            if (!node_is_ancestor(cur, n))
                                if (step_push(ns, cur, alloc) & once) return;
                        }

                        cur = cur->prev_sibling_c;
                    }
                }

                break;
            }

            case axis_ancestor:
            case axis_ancestor_or_self: {
                if (axis == axis_ancestor_or_self)
                    if (step_push(ns, n, alloc) & once) return;

                xml_node_struct* cur = n->parent;

                while (cur) {
                    if (step_push(ns, cur, alloc) & once) return;

                    cur = cur->parent;
                }

                break;
            }

            case axis_self: {
                step_push(ns, n, alloc);

                break;
            }

            case axis_parent: {
                if (n->parent) step_push(ns, n->parent, alloc);

                break;
            }

            default:
                assert(false && "Unimplemented axis");    // unreachable
        }
    }

    template<class T>
    void step_fill(xpath_node_set_raw& ns, xml_attribute_struct* a, xml_node_struct* p, xpath_allocator* alloc, bool once, T v)
    {
        const axis_t axis = T::axis;

        switch (axis) {
            case axis_ancestor:
            case axis_ancestor_or_self: {
                if (axis == axis_ancestor_or_self && _test == nodetest_type_node)    // reject attributes based on principal node type test
                    if (step_push(ns, a, p, alloc) & once) return;

                xml_node_struct* cur = p;

                while (cur) {
                    if (step_push(ns, cur, alloc) & once) return;

                    cur = cur->parent;
                }

                break;
            }

            case axis_descendant_or_self:
            case axis_self: {
                if (_test == nodetest_type_node)    // reject attributes based on principal node type test
                    step_push(ns, a, p, alloc);

                break;
            }

            case axis_following: {
                xml_node_struct* cur = p;

                while (cur) {
                    if (cur->first_child)
                        cur = cur->first_child;
                    else {
                        while (!cur->next_sibling) {
                            cur = cur->parent;

                            if (!cur) return;
                        }

                        cur = cur->next_sibling;
                    }

                    if (step_push(ns, cur, alloc) & once) return;
                }

                break;
            }

            case axis_parent: {
                step_push(ns, p, alloc);

                break;
            }

            case axis_preceding: {
                // preceding:: axis does not include attribute nodes and attribute ancestors (they are the same as parent's ancestors), so
                // we can reuse node preceding
                step_fill(ns, p, alloc, once, v);
                break;
            }

            default:
                assert(false && "Unimplemented axis");    // unreachable
        }
    }

    template<class T>
    void step_fill(xpath_node_set_raw& ns, const xpath_node& xn, xpath_allocator* alloc, bool once, T v)
    {
        const axis_t axis                = T::axis;
        const bool   axis_has_attributes = (axis == axis_ancestor || axis == axis_ancestor_or_self || axis == axis_descendant_or_self ||
                                          axis == axis_following || axis == axis_parent || axis == axis_preceding || axis == axis_self);

        if (xn.node())
            step_fill(ns, xn.node().internal_object(), alloc, once, v);
        else if (axis_has_attributes && xn.attribute() && xn.parent())
            step_fill(ns, xn.attribute().internal_object(), xn.parent().internal_object(), alloc, once, v);
    }

    template<class T>
    xpath_node_set_raw step_do(const xpath_context& c, const xpath_stack& stack, nodeset_eval_t eval, T v)
    {
        const axis_t axis = T::axis;
        const bool   axis_reverse =
            (axis == axis_ancestor || axis == axis_ancestor_or_self || axis == axis_preceding || axis == axis_preceding_sibling);
        const xpath_node_set::type_t axis_type = axis_reverse ? xpath_node_set::type_sorted_reverse : xpath_node_set::type_sorted;

        bool once = (axis == axis_attribute && _test == nodetest_name) || (!_right && eval_once(axis_type, eval)) ||
                    // coverity[mixed_enums]
                    (_right && !_right->_next && _right->_test == predicate_constant_one);

        xpath_node_set_raw ns;
        ns.set_type(axis_type);

        if (_left) {
            xpath_node_set_raw s = _left->eval_node_set(c, stack, nodeset_eval_all);

            // self axis preserves the original order
            if (axis == axis_self) ns.set_type(s.type());

            for (const xpath_node* it = s.begin(); it != s.end(); ++it) {
                size_t size = ns.size();

                // in general, all axes generate elements in a particular order, but there is no order guarantee if axis is applied to two
                // nodes
                if (axis != axis_self && size != 0) ns.set_type(xpath_node_set::type_unsorted);

                step_fill(ns, *it, stack.result, once, v);
                if (_right) apply_predicates(ns, size, stack, eval);
            }
        }
        else {
            step_fill(ns, c.n, stack.result, once, v);
            if (_right) apply_predicates(ns, 0, stack, eval);
        }

        // child, attribute and self axes always generate unique set of nodes
        // for other axis, if the set stayed sorted, it stayed unique because the traversal algorithms do not visit the same node twice
        if (axis != axis_child && axis != axis_attribute && axis != axis_self && ns.type() == xpath_node_set::type_unsorted)
            ns.remove_duplicates(stack.temp);

        return ns;
    }

public:
    xpath_ast_node(ast_type_t type, xpath_value_type rettype_, const char_t* value)
        : _type(static_cast<char>(type)),
          _rettype(static_cast<char>(rettype_)),
          _axis(0),
          _test(0),
          _left(0),
          _right(0),
          _next(0)
    {
        assert(type == ast_string_constant);
        _data.string = value;
    }

    xpath_ast_node(ast_type_t type, xpath_value_type rettype_, double value)
        : _type(static_cast<char>(type)),
          _rettype(static_cast<char>(rettype_)),
          _axis(0),
          _test(0),
          _left(0),
          _right(0),
          _next(0)
    {
        assert(type == ast_number_constant);
        _data.number = value;
    }

    xpath_ast_node(ast_type_t type, xpath_value_type rettype_, xpath_variable* value)
        : _type(static_cast<char>(type)),
          _rettype(static_cast<char>(rettype_)),
          _axis(0),
          _test(0),
          _left(0),
          _right(0),
          _next(0)
    {
        assert(type == ast_variable);
        _data.variable = value;
    }

    xpath_ast_node(ast_type_t type, xpath_value_type rettype_, xpath_ast_node* left = 0, xpath_ast_node* right = 0)
        : _type(static_cast<char>(type)),
          _rettype(static_cast<char>(rettype_)),
          _axis(0),
          _test(0),
          _left(left),
          _right(right),
          _next(0)
    {}

    xpath_ast_node(ast_type_t type, xpath_ast_node* left, axis_t axis, nodetest_t test, const char_t* contents)
        : _type(static_cast<char>(type)),
          _rettype(xpath_type_node_set),
          _axis(static_cast<char>(axis)),
          _test(static_cast<char>(test)),
          _left(left),
          _right(0),
          _next(0)
    {
        assert(type == ast_step);
        _data.nodetest = contents;
    }

    xpath_ast_node(ast_type_t type, xpath_ast_node* left, xpath_ast_node* right, predicate_t test)
        : _type(static_cast<char>(type)),
          _rettype(xpath_type_node_set),
          _axis(0),
          _test(static_cast<char>(test)),
          _left(left),
          _right(right),
          _next(0)
    {
        assert(type == ast_filter || type == ast_predicate);
    }

    void set_next(xpath_ast_node* value)
    {
        _next = value;
    }

    void set_right(xpath_ast_node* value)
    {
        _right = value;
    }

    bool eval_boolean(const xpath_context& c, const xpath_stack& stack)
    {
        switch (_type) {
            case ast_op_or:
                return _left->eval_boolean(c, stack) || _right->eval_boolean(c, stack);

            case ast_op_and:
                return _left->eval_boolean(c, stack) && _right->eval_boolean(c, stack);

            case ast_op_equal:
                return compare_eq(_left, _right, c, stack, equal_to());

            case ast_op_not_equal:
                return compare_eq(_left, _right, c, stack, not_equal_to());

            case ast_op_less:
                return compare_rel(_left, _right, c, stack, less());

            case ast_op_greater:
                return compare_rel(_right, _left, c, stack, less());

            case ast_op_less_or_equal:
                return compare_rel(_left, _right, c, stack, less_equal());

            case ast_op_greater_or_equal:
                return compare_rel(_right, _left, c, stack, less_equal());

            case ast_func_starts_with: {
                xpath_allocator_capture cr(stack.result);

                xpath_string lr = _left->eval_string(c, stack);
                xpath_string rr = _right->eval_string(c, stack);

                return starts_with(lr.c_str(), rr.c_str());
            }

            case ast_func_contains: {
                xpath_allocator_capture cr(stack.result);

                xpath_string lr = _left->eval_string(c, stack);
                xpath_string rr = _right->eval_string(c, stack);

                return find_substring(lr.c_str(), rr.c_str()) != 0;
            }

            case ast_func_boolean:
                return _left->eval_boolean(c, stack);

            case ast_func_not:
                return !_left->eval_boolean(c, stack);

            case ast_func_true:
                return true;

            case ast_func_false:
                return false;

            case ast_func_lang: {
                if (c.n.attribute()) return false;

                xpath_allocator_capture cr(stack.result);

                xpath_string lang = _left->eval_string(c, stack);

                for (xml_node n = c.n.node(); n; n = n.parent()) {
                    xml_attribute a = n.attribute(PUGIXML_TEXT("xml:lang"));

                    if (a) {
                        const char_t* value = a.value();

                        // strnicmp / strncasecmp is not portable
                        for (const char_t* lit = lang.c_str(); *lit; ++lit) {
                            if (tolower_ascii(*lit) != tolower_ascii(*value)) return false;
                            ++value;
                        }

                        return *value == 0 || *value == '-';
                    }
                }

                return false;
            }

            case ast_opt_compare_attribute: {
                const char_t* value = (_right->_type == ast_string_constant) ? _right->_data.string : _right->_data.variable->get_string();

                xml_attribute attr = c.n.node().attribute(_left->_data.nodetest);

                return attr && strequal(attr.value(), value) && is_xpath_attribute(attr.name());
            }

            case ast_variable: {
                assert(_rettype == _data.variable->type());

                if (_rettype == xpath_type_boolean) return _data.variable->get_boolean();
            }

            // fallthrough
            default: {
                switch (_rettype) {
                    case xpath_type_number:
                        return convert_number_to_boolean(eval_number(c, stack));

                    case xpath_type_string: {
                        xpath_allocator_capture cr(stack.result);

                        return !eval_string(c, stack).empty();
                    }

                    case xpath_type_node_set: {
                        xpath_allocator_capture cr(stack.result);

                        return !eval_node_set(c, stack, nodeset_eval_any).empty();
                    }

                    default:
                        assert(false && "Wrong expression for return type boolean");    // unreachable
                        return false;
                }
            }
        }
    }

    double eval_number(const xpath_context& c, const xpath_stack& stack)
    {
        switch (_type) {
            case ast_op_add:
                return _left->eval_number(c, stack) + _right->eval_number(c, stack);

            case ast_op_subtract:
                return _left->eval_number(c, stack) - _right->eval_number(c, stack);

            case ast_op_multiply:
                return _left->eval_number(c, stack) * _right->eval_number(c, stack);

            case ast_op_divide:
                return _left->eval_number(c, stack) / _right->eval_number(c, stack);

            case ast_op_mod:
                return fmod(_left->eval_number(c, stack), _right->eval_number(c, stack));

            case ast_op_negate:
                return -_left->eval_number(c, stack);

            case ast_number_constant:
                return _data.number;

            case ast_func_last:
                return static_cast<double>(c.size);

            case ast_func_position:
                return static_cast<double>(c.position);

            case ast_func_count: {
                xpath_allocator_capture cr(stack.result);

                return static_cast<double>(_left->eval_node_set(c, stack, nodeset_eval_all).size());
            }

            case ast_func_string_length_0: {
                xpath_allocator_capture cr(stack.result);

                return static_cast<double>(string_value(c.n, stack.result).length());
            }

            case ast_func_string_length_1: {
                xpath_allocator_capture cr(stack.result);

                return static_cast<double>(_left->eval_string(c, stack).length());
            }

            case ast_func_number_0: {
                xpath_allocator_capture cr(stack.result);

                return convert_string_to_number(string_value(c.n, stack.result).c_str());
            }

            case ast_func_number_1:
                return _left->eval_number(c, stack);

            case ast_func_sum: {
                xpath_allocator_capture cr(stack.result);

                double r = 0;

                xpath_node_set_raw ns = _left->eval_node_set(c, stack, nodeset_eval_all);

                for (const xpath_node* it = ns.begin(); it != ns.end(); ++it) {
                    xpath_allocator_capture cri(stack.result);

                    r += convert_string_to_number(string_value(*it, stack.result).c_str());
                }

                return r;
            }

            case ast_func_floor: {
                double r = _left->eval_number(c, stack);

                return r == r ? floor(r) : r;
            }

            case ast_func_ceiling: {
                double r = _left->eval_number(c, stack);

                return r == r ? ceil(r) : r;
            }

            case ast_func_round:
                return round_nearest_nzero(_left->eval_number(c, stack));

            case ast_variable: {
                assert(_rettype == _data.variable->type());

                if (_rettype == xpath_type_number) return _data.variable->get_number();
            }

            // fallthrough
            default: {
                switch (_rettype) {
                    case xpath_type_boolean:
                        return eval_boolean(c, stack) ? 1 : 0;

                    case xpath_type_string: {
                        xpath_allocator_capture cr(stack.result);

                        return convert_string_to_number(eval_string(c, stack).c_str());
                    }

                    case xpath_type_node_set: {
                        xpath_allocator_capture cr(stack.result);

                        return convert_string_to_number(eval_string(c, stack).c_str());
                    }

                    default:
                        assert(false && "Wrong expression for return type number");    // unreachable
                        return 0;
                }
            }
        }
    }

    xpath_string eval_string_concat(const xpath_context& c, const xpath_stack& stack)
    {
        assert(_type == ast_func_concat);

        xpath_allocator_capture ct(stack.temp);

        // count the string number
        size_t count = 1;
        for (xpath_ast_node* nc = _right; nc; nc = nc->_next) count++;

        // allocate a buffer for temporary string objects
        xpath_string* buffer = static_cast<xpath_string*>(stack.temp->allocate(count * sizeof(xpath_string)));
        if (!buffer) return xpath_string();

        // evaluate all strings to temporary stack
        xpath_stack swapped_stack = { stack.temp, stack.result };

        buffer[0] = _left->eval_string(c, swapped_stack);

        size_t pos = 1;
        for (xpath_ast_node* n = _right; n; n = n->_next, ++pos) buffer[pos] = n->eval_string(c, swapped_stack);
        assert(pos == count);

        // get total length
        size_t length = 0;
        for (size_t i = 0; i < count; ++i) length += buffer[i].length();

        // create final string
        char_t* result = static_cast<char_t*>(stack.result->allocate((length + 1) * sizeof(char_t)));
        if (!result) return xpath_string();

        char_t* ri = result;

        for (size_t j = 0; j < count; ++j)
            for (const char_t* bi = buffer[j].c_str(); *bi; ++bi) *ri++ = *bi;

        *ri = 0;

        return xpath_string::from_heap_preallocated(result, ri);
    }

    xpath_string eval_string(const xpath_context& c, const xpath_stack& stack)
    {
        switch (_type) {
            case ast_string_constant:
                return xpath_string::from_const(_data.string);

            case ast_func_local_name_0: {
                xpath_node na = c.n;

                return xpath_string::from_const(local_name(na));
            }

            case ast_func_local_name_1: {
                xpath_allocator_capture cr(stack.result);

                xpath_node_set_raw ns = _left->eval_node_set(c, stack, nodeset_eval_first);
                xpath_node         na = ns.first();

                return xpath_string::from_const(local_name(na));
            }

            case ast_func_name_0: {
                xpath_node na = c.n;

                return xpath_string::from_const(qualified_name(na));
            }

            case ast_func_name_1: {
                xpath_allocator_capture cr(stack.result);

                xpath_node_set_raw ns = _left->eval_node_set(c, stack, nodeset_eval_first);
                xpath_node         na = ns.first();

                return xpath_string::from_const(qualified_name(na));
            }

            case ast_func_namespace_uri_0: {
                xpath_node na = c.n;

                return xpath_string::from_const(namespace_uri(na));
            }

            case ast_func_namespace_uri_1: {
                xpath_allocator_capture cr(stack.result);

                xpath_node_set_raw ns = _left->eval_node_set(c, stack, nodeset_eval_first);
                xpath_node         na = ns.first();

                return xpath_string::from_const(namespace_uri(na));
            }

            case ast_func_string_0:
                return string_value(c.n, stack.result);

            case ast_func_string_1:
                return _left->eval_string(c, stack);

            case ast_func_concat:
                return eval_string_concat(c, stack);

            case ast_func_substring_before: {
                xpath_allocator_capture cr(stack.temp);

                xpath_stack swapped_stack = { stack.temp, stack.result };

                xpath_string s = _left->eval_string(c, swapped_stack);
                xpath_string p = _right->eval_string(c, swapped_stack);

                const char_t* pos = find_substring(s.c_str(), p.c_str());

                return pos ? xpath_string::from_heap(s.c_str(), pos, stack.result) : xpath_string();
            }

            case ast_func_substring_after: {
                xpath_allocator_capture cr(stack.temp);

                xpath_stack swapped_stack = { stack.temp, stack.result };

                xpath_string s = _left->eval_string(c, swapped_stack);
                xpath_string p = _right->eval_string(c, swapped_stack);

                const char_t* pos = find_substring(s.c_str(), p.c_str());
                if (!pos) return xpath_string();

                const char_t* rbegin = pos + p.length();
                const char_t* rend   = s.c_str() + s.length();

                return s.uses_heap() ? xpath_string::from_heap(rbegin, rend, stack.result) : xpath_string::from_const(rbegin);
            }

            case ast_func_substring_2: {
                xpath_allocator_capture cr(stack.temp);

                xpath_stack swapped_stack = { stack.temp, stack.result };

                xpath_string s        = _left->eval_string(c, swapped_stack);
                size_t       s_length = s.length();

                double first = round_nearest(_right->eval_number(c, stack));

                if (is_nan(first))
                    return xpath_string();    // NaN
                else if (first >= s_length + 1)
                    return xpath_string();

                size_t pos = first < 1 ? 1 : static_cast<size_t>(first);
                assert(1 <= pos && pos <= s_length + 1);

                const char_t* rbegin = s.c_str() + (pos - 1);
                const char_t* rend   = s.c_str() + s.length();

                return s.uses_heap() ? xpath_string::from_heap(rbegin, rend, stack.result) : xpath_string::from_const(rbegin);
            }

            case ast_func_substring_3: {
                xpath_allocator_capture cr(stack.temp);

                xpath_stack swapped_stack = { stack.temp, stack.result };

                xpath_string s        = _left->eval_string(c, swapped_stack);
                size_t       s_length = s.length();

                double first = round_nearest(_right->eval_number(c, stack));
                double last  = first + round_nearest(_right->_next->eval_number(c, stack));

                if (is_nan(first) || is_nan(last))
                    return xpath_string();
                else if (first >= s_length + 1)
                    return xpath_string();
                else if (first >= last)
                    return xpath_string();
                else if (last < 1)
                    return xpath_string();

                size_t pos = first < 1 ? 1 : static_cast<size_t>(first);
                size_t end = last >= s_length + 1 ? s_length + 1 : static_cast<size_t>(last);

                assert(1 <= pos && pos <= end && end <= s_length + 1);
                const char_t* rbegin = s.c_str() + (pos - 1);
                const char_t* rend   = s.c_str() + (end - 1);

                return (end == s_length + 1 && !s.uses_heap()) ? xpath_string::from_const(rbegin)
                                                               : xpath_string::from_heap(rbegin, rend, stack.result);
            }

            case ast_func_normalize_space_0: {
                xpath_string s = string_value(c.n, stack.result);

                char_t* begin = s.data(stack.result);
                if (!begin) return xpath_string();

                char_t* end = normalize_space(begin);

                return xpath_string::from_heap_preallocated(begin, end);
            }

            case ast_func_normalize_space_1: {
                xpath_string s = _left->eval_string(c, stack);

                char_t* begin = s.data(stack.result);
                if (!begin) return xpath_string();

                char_t* end = normalize_space(begin);

                return xpath_string::from_heap_preallocated(begin, end);
            }

            case ast_func_translate: {
                xpath_allocator_capture cr(stack.temp);

                xpath_stack swapped_stack = { stack.temp, stack.result };

                xpath_string s    = _left->eval_string(c, stack);
                xpath_string from = _right->eval_string(c, swapped_stack);
                xpath_string to   = _right->_next->eval_string(c, swapped_stack);

                char_t* begin = s.data(stack.result);
                if (!begin) return xpath_string();

                char_t* end = translate(begin, from.c_str(), to.c_str(), to.length());

                return xpath_string::from_heap_preallocated(begin, end);
            }

            case ast_opt_translate_table: {
                xpath_string s = _left->eval_string(c, stack);

                char_t* begin = s.data(stack.result);
                if (!begin) return xpath_string();

                char_t* end = translate_table(begin, _data.table);

                return xpath_string::from_heap_preallocated(begin, end);
            }

            case ast_variable: {
                assert(_rettype == _data.variable->type());

                if (_rettype == xpath_type_string) return xpath_string::from_const(_data.variable->get_string());
            }

            // fallthrough
            default: {
                switch (_rettype) {
                    case xpath_type_boolean:
                        return xpath_string::from_const(eval_boolean(c, stack) ? PUGIXML_TEXT("true") : PUGIXML_TEXT("false"));

                    case xpath_type_number:
                        return convert_number_to_string(eval_number(c, stack), stack.result);

                    case xpath_type_node_set: {
                        xpath_allocator_capture cr(stack.temp);

                        xpath_stack swapped_stack = { stack.temp, stack.result };

                        xpath_node_set_raw ns = eval_node_set(c, swapped_stack, nodeset_eval_first);
                        return ns.empty() ? xpath_string() : string_value(ns.first(), stack.result);
                    }

                    default:
                        assert(false && "Wrong expression for return type string");    // unreachable
                        return xpath_string();
                }
            }
        }
    }

    xpath_node_set_raw eval_node_set(const xpath_context& c, const xpath_stack& stack, nodeset_eval_t eval)
    {
        switch (_type) {
            case ast_op_union: {
                xpath_allocator_capture cr(stack.temp);

                xpath_stack swapped_stack = { stack.temp, stack.result };

                xpath_node_set_raw ls = _left->eval_node_set(c, stack, eval);
                xpath_node_set_raw rs = _right->eval_node_set(c, swapped_stack, eval);

                // we can optimize merging two sorted sets, but this is a very rare operation, so don't bother
                ls.set_type(xpath_node_set::type_unsorted);

                ls.append(rs.begin(), rs.end(), stack.result);
                ls.remove_duplicates(stack.temp);

                return ls;
            }

            case ast_filter: {
                xpath_node_set_raw set =
                    _left->eval_node_set(c, stack, _test == predicate_constant_one ? nodeset_eval_first : nodeset_eval_all);

                // either expression is a number or it contains position() call; sort by document order
                if (_test != predicate_posinv) set.sort_do();

                bool once = eval_once(set.type(), eval);

                apply_predicate(set, 0, stack, once);

                return set;
            }

            case ast_func_id:
                return xpath_node_set_raw();

            case ast_step: {
                switch (_axis) {
                    case axis_ancestor:
                        return step_do(c, stack, eval, axis_to_type<axis_ancestor>());

                    case axis_ancestor_or_self:
                        return step_do(c, stack, eval, axis_to_type<axis_ancestor_or_self>());

                    case axis_attribute:
                        return step_do(c, stack, eval, axis_to_type<axis_attribute>());

                    case axis_child:
                        return step_do(c, stack, eval, axis_to_type<axis_child>());

                    case axis_descendant:
                        return step_do(c, stack, eval, axis_to_type<axis_descendant>());

                    case axis_descendant_or_self:
                        return step_do(c, stack, eval, axis_to_type<axis_descendant_or_self>());

                    case axis_following:
                        return step_do(c, stack, eval, axis_to_type<axis_following>());

                    case axis_following_sibling:
                        return step_do(c, stack, eval, axis_to_type<axis_following_sibling>());

                    case axis_namespace:
                        // namespaced axis is not supported
                        return xpath_node_set_raw();

                    case axis_parent:
                        return step_do(c, stack, eval, axis_to_type<axis_parent>());

                    case axis_preceding:
                        return step_do(c, stack, eval, axis_to_type<axis_preceding>());

                    case axis_preceding_sibling:
                        return step_do(c, stack, eval, axis_to_type<axis_preceding_sibling>());

                    case axis_self:
                        return step_do(c, stack, eval, axis_to_type<axis_self>());

                    default:
                        assert(false && "Unknown axis");    // unreachable
                        return xpath_node_set_raw();
                }
            }

            case ast_step_root: {
                assert(!_right);    // root step can't have any predicates

                xpath_node_set_raw ns;

                ns.set_type(xpath_node_set::type_sorted);

                if (c.n.node())
                    ns.push_back(c.n.node().root(), stack.result);
                else if (c.n.attribute())
                    ns.push_back(c.n.parent().root(), stack.result);

                return ns;
            }

            case ast_variable: {
                assert(_rettype == _data.variable->type());

                if (_rettype == xpath_type_node_set) {
                    const xpath_node_set& s = _data.variable->get_node_set();

                    xpath_node_set_raw ns;

                    ns.set_type(s.type());
                    ns.append(s.begin(), s.end(), stack.result);

                    return ns;
                }
            }

            // fallthrough
            default:
                assert(false && "Wrong expression for return type node set");    // unreachable
                return xpath_node_set_raw();
        }
    }

    void optimize(xpath_allocator* alloc)
    {
        if (_left) _left->optimize(alloc);

        if (_right) _right->optimize(alloc);

        if (_next) _next->optimize(alloc);

        // coverity[var_deref_model]
        optimize_self(alloc);
    }

    void optimize_self(xpath_allocator* alloc)
    {
        // Rewrite [position()=expr] with [expr]
        // Note that this step has to go before classification to recognize [position()=1]
        if ((_type == ast_filter || _type == ast_predicate) &&
            _right &&    // workaround for clang static analyzer (_right is never null for ast_filter/ast_predicate)
            _right->_type == ast_op_equal && _right->_left->_type == ast_func_position && _right->_right->_rettype == xpath_type_number)
        {
            _right = _right->_right;
        }

        // Classify filter/predicate ops to perform various optimizations during evaluation
        if ((_type == ast_filter || _type == ast_predicate) &&
            _right)    // workaround for clang static analyzer (_right is never null for ast_filter/ast_predicate)
        {
            assert(_test == predicate_default);

            if (_right->_type == ast_number_constant && _right->_data.number == 1.0)
                _test = predicate_constant_one;
            else if (_right->_rettype == xpath_type_number &&
                     (_right->_type == ast_number_constant || _right->_type == ast_variable || _right->_type == ast_func_last))
                _test = predicate_constant;
            else if (_right->_rettype != xpath_type_number && _right->is_posinv_expr())
                _test = predicate_posinv;
        }

        // Rewrite descendant-or-self::node()/child::foo with descendant::foo
        // The former is a full form of //foo, the latter is much faster since it executes the node test immediately
        // Do a similar kind of rewrite for self/descendant/descendant-or-self axes
        // Note that we only rewrite positionally invariant steps (//foo[1] != /descendant::foo[1])
        if (_type == ast_step &&
            (_axis == axis_child || _axis == axis_self || _axis == axis_descendant || _axis == axis_descendant_or_self) && _left &&
            _left->_type == ast_step && _left->_axis == axis_descendant_or_self && _left->_test == nodetest_type_node && !_left->_right &&
            is_posinv_step())
        {
            if (_axis == axis_child || _axis == axis_descendant)
                _axis = axis_descendant;
            else
                _axis = axis_descendant_or_self;

            _left = _left->_left;
        }

        // Use optimized lookup table implementation for translate() with constant arguments
        if (_type == ast_func_translate &&
            _right &&    // workaround for clang static analyzer (_right is never null for ast_func_translate)
            _right->_type == ast_string_constant && _right->_next->_type == ast_string_constant)
        {
            unsigned char* table = translate_table_generate(alloc, _right->_data.string, _right->_next->_data.string);

            if (table) {
                _type       = ast_opt_translate_table;
                _data.table = table;
            }
        }

        // Use optimized path for @attr = 'value' or @attr = $value
        if (_type == ast_op_equal && _left && _right &&    // workaround for clang static analyzer and Coverity (_left and _right are never
                                                           // null for ast_op_equal) coverity[mixed_enums]
            _left->_type == ast_step && _left->_axis == axis_attribute && _left->_test == nodetest_name && !_left->_left &&
            !_left->_right &&
            (_right->_type == ast_string_constant || (_right->_type == ast_variable && _right->_rettype == xpath_type_string)))
        {
            _type = ast_opt_compare_attribute;
        }
    }

    bool is_posinv_expr() const
    {
        switch (_type) {
            case ast_func_position:
            case ast_func_last:
                return false;

            case ast_string_constant:
            case ast_number_constant:
            case ast_variable:
                return true;

            case ast_step:
            case ast_step_root:
                return true;

            case ast_predicate:
            case ast_filter:
                return true;

            default:
                if (_left && !_left->is_posinv_expr()) return false;

                for (xpath_ast_node* n = _right; n; n = n->_next)
                    if (!n->is_posinv_expr()) return false;

                return true;
        }
    }

    bool is_posinv_step() const
    {
        assert(_type == ast_step);

        for (xpath_ast_node* n = _right; n; n = n->_next) {
            assert(n->_type == ast_predicate);

            if (n->_test != predicate_posinv) return false;
        }

        return true;
    }

    xpath_value_type rettype() const
    {
        return static_cast<xpath_value_type>(_rettype);
    }
};

struct xpath_parser
{
    xpath_allocator* _alloc;
    xpath_lexer      _lexer;

    const char_t*       _query;
    xpath_variable_set* _variables;

    xpath_parse_result* _result;

    char_t _scratch[32];

    xpath_ast_node* error(const char* message)
    {
        _result->error  = message;
        _result->offset = _lexer.current_pos() - _query;

        return 0;
    }

    xpath_ast_node* error_oom()
    {
        assert(_alloc->_error);
        *_alloc->_error = true;

        return 0;
    }

    void* alloc_node()
    {
        return _alloc->allocate(sizeof(xpath_ast_node));
    }

    xpath_ast_node* alloc_node(ast_type_t type, xpath_value_type rettype, const char_t* value)
    {
        void* memory = alloc_node();
        return memory ? new (memory) xpath_ast_node(type, rettype, value) : 0;
    }

    xpath_ast_node* alloc_node(ast_type_t type, xpath_value_type rettype, double value)
    {
        void* memory = alloc_node();
        return memory ? new (memory) xpath_ast_node(type, rettype, value) : 0;
    }

    xpath_ast_node* alloc_node(ast_type_t type, xpath_value_type rettype, xpath_variable* value)
    {
        void* memory = alloc_node();
        return memory ? new (memory) xpath_ast_node(type, rettype, value) : 0;
    }

    xpath_ast_node* alloc_node(ast_type_t type, xpath_value_type rettype, xpath_ast_node* left = 0, xpath_ast_node* right = 0)
    {
        void* memory = alloc_node();
        return memory ? new (memory) xpath_ast_node(type, rettype, left, right) : 0;
    }

    xpath_ast_node* alloc_node(ast_type_t type, xpath_ast_node* left, axis_t axis, nodetest_t test, const char_t* contents)
    {
        void* memory = alloc_node();
        return memory ? new (memory) xpath_ast_node(type, left, axis, test, contents) : 0;
    }

    xpath_ast_node* alloc_node(ast_type_t type, xpath_ast_node* left, xpath_ast_node* right, predicate_t test)
    {
        void* memory = alloc_node();
        return memory ? new (memory) xpath_ast_node(type, left, right, test) : 0;
    }

    const char_t* alloc_string(const xpath_lexer_string& value)
    {
        if (!value.begin) return PUGIXML_TEXT("");

        size_t length = static_cast<size_t>(value.end - value.begin);

        char_t* c = static_cast<char_t*>(_alloc->allocate((length + 1) * sizeof(char_t)));
        if (!c) return 0;

        memcpy(c, value.begin, length * sizeof(char_t));
        c[length] = 0;

        return c;
    }

    xpath_ast_node* parse_function(const xpath_lexer_string& name, size_t argc, xpath_ast_node* args[2])
    {
        switch (name.begin[0]) {
            case 'b':
                if (name == PUGIXML_TEXT("boolean") && argc == 1) return alloc_node(ast_func_boolean, xpath_type_boolean, args[0]);

                break;

            case 'c':
                if (name == PUGIXML_TEXT("count") && argc == 1) {
                    if (args[0]->rettype() != xpath_type_node_set) return error("Function has to be applied to node set");
                    return alloc_node(ast_func_count, xpath_type_number, args[0]);
                }
                else if (name == PUGIXML_TEXT("contains") && argc == 2)
                    return alloc_node(ast_func_contains, xpath_type_boolean, args[0], args[1]);
                else if (name == PUGIXML_TEXT("concat") && argc >= 2)
                    return alloc_node(ast_func_concat, xpath_type_string, args[0], args[1]);
                else if (name == PUGIXML_TEXT("ceiling") && argc == 1)
                    return alloc_node(ast_func_ceiling, xpath_type_number, args[0]);

                break;

            case 'f':
                if (name == PUGIXML_TEXT("false") && argc == 0)
                    return alloc_node(ast_func_false, xpath_type_boolean);
                else if (name == PUGIXML_TEXT("floor") && argc == 1)
                    return alloc_node(ast_func_floor, xpath_type_number, args[0]);

                break;

            case 'i':
                if (name == PUGIXML_TEXT("id") && argc == 1) return alloc_node(ast_func_id, xpath_type_node_set, args[0]);

                break;

            case 'l':
                if (name == PUGIXML_TEXT("last") && argc == 0)
                    return alloc_node(ast_func_last, xpath_type_number);
                else if (name == PUGIXML_TEXT("lang") && argc == 1)
                    return alloc_node(ast_func_lang, xpath_type_boolean, args[0]);
                else if (name == PUGIXML_TEXT("local-name") && argc <= 1) {
                    if (argc == 1 && args[0]->rettype() != xpath_type_node_set) return error("Function has to be applied to node set");
                    return alloc_node(argc == 0 ? ast_func_local_name_0 : ast_func_local_name_1, xpath_type_string, args[0]);
                }

                break;

            case 'n':
                if (name == PUGIXML_TEXT("name") && argc <= 1) {
                    if (argc == 1 && args[0]->rettype() != xpath_type_node_set) return error("Function has to be applied to node set");
                    return alloc_node(argc == 0 ? ast_func_name_0 : ast_func_name_1, xpath_type_string, args[0]);
                }
                else if (name == PUGIXML_TEXT("namespace-uri") && argc <= 1) {
                    if (argc == 1 && args[0]->rettype() != xpath_type_node_set) return error("Function has to be applied to node set");
                    return alloc_node(argc == 0 ? ast_func_namespace_uri_0 : ast_func_namespace_uri_1, xpath_type_string, args[0]);
                }
                else if (name == PUGIXML_TEXT("normalize-space") && argc <= 1)
                    return alloc_node(argc == 0 ? ast_func_normalize_space_0 : ast_func_normalize_space_1,
                                      xpath_type_string,
                                      args[0],
                                      args[1]);
                else if (name == PUGIXML_TEXT("not") && argc == 1)
                    return alloc_node(ast_func_not, xpath_type_boolean, args[0]);
                else if (name == PUGIXML_TEXT("number") && argc <= 1)
                    return alloc_node(argc == 0 ? ast_func_number_0 : ast_func_number_1, xpath_type_number, args[0]);

                break;

            case 'p':
                if (name == PUGIXML_TEXT("position") && argc == 0) return alloc_node(ast_func_position, xpath_type_number);

                break;

            case 'r':
                if (name == PUGIXML_TEXT("round") && argc == 1) return alloc_node(ast_func_round, xpath_type_number, args[0]);

                break;

            case 's':
                if (name == PUGIXML_TEXT("string") && argc <= 1)
                    return alloc_node(argc == 0 ? ast_func_string_0 : ast_func_string_1, xpath_type_string, args[0]);
                else if (name == PUGIXML_TEXT("string-length") && argc <= 1)
                    return alloc_node(argc == 0 ? ast_func_string_length_0 : ast_func_string_length_1, xpath_type_number, args[0]);
                else if (name == PUGIXML_TEXT("starts-with") && argc == 2)
                    return alloc_node(ast_func_starts_with, xpath_type_boolean, args[0], args[1]);
                else if (name == PUGIXML_TEXT("substring-before") && argc == 2)
                    return alloc_node(ast_func_substring_before, xpath_type_string, args[0], args[1]);
                else if (name == PUGIXML_TEXT("substring-after") && argc == 2)
                    return alloc_node(ast_func_substring_after, xpath_type_string, args[0], args[1]);
                else if (name == PUGIXML_TEXT("substring") && (argc == 2 || argc == 3))
                    return alloc_node(argc == 2 ? ast_func_substring_2 : ast_func_substring_3, xpath_type_string, args[0], args[1]);
                else if (name == PUGIXML_TEXT("sum") && argc == 1) {
                    if (args[0]->rettype() != xpath_type_node_set) return error("Function has to be applied to node set");
                    return alloc_node(ast_func_sum, xpath_type_number, args[0]);
                }

                break;

            case 't':
                if (name == PUGIXML_TEXT("translate") && argc == 3)
                    return alloc_node(ast_func_translate, xpath_type_string, args[0], args[1]);
                else if (name == PUGIXML_TEXT("true") && argc == 0)
                    return alloc_node(ast_func_true, xpath_type_boolean);

                break;

            default:
                break;
        }

        return error("Unrecognized function or wrong parameter count");
    }

    axis_t parse_axis_name(const xpath_lexer_string& name, bool& specified)
    {
        specified = true;

        switch (name.begin[0]) {
            case 'a':
                if (name == PUGIXML_TEXT("ancestor"))
                    return axis_ancestor;
                else if (name == PUGIXML_TEXT("ancestor-or-self"))
                    return axis_ancestor_or_self;
                else if (name == PUGIXML_TEXT("attribute"))
                    return axis_attribute;

                break;

            case 'c':
                if (name == PUGIXML_TEXT("child")) return axis_child;

                break;

            case 'd':
                if (name == PUGIXML_TEXT("descendant"))
                    return axis_descendant;
                else if (name == PUGIXML_TEXT("descendant-or-self"))
                    return axis_descendant_or_self;

                break;

            case 'f':
                if (name == PUGIXML_TEXT("following"))
                    return axis_following;
                else if (name == PUGIXML_TEXT("following-sibling"))
                    return axis_following_sibling;

                break;

            case 'n':
                if (name == PUGIXML_TEXT("namespace")) return axis_namespace;

                break;

            case 'p':
                if (name == PUGIXML_TEXT("parent"))
                    return axis_parent;
                else if (name == PUGIXML_TEXT("preceding"))
                    return axis_preceding;
                else if (name == PUGIXML_TEXT("preceding-sibling"))
                    return axis_preceding_sibling;

                break;

            case 's':
                if (name == PUGIXML_TEXT("self")) return axis_self;

                break;

            default:
                break;
        }

        specified = false;
        return axis_child;
    }

    nodetest_t parse_node_test_type(const xpath_lexer_string& name)
    {
        switch (name.begin[0]) {
            case 'c':
                if (name == PUGIXML_TEXT("comment")) return nodetest_type_comment;

                break;

            case 'n':
                if (name == PUGIXML_TEXT("node")) return nodetest_type_node;

                break;

            case 'p':
                if (name == PUGIXML_TEXT("processing-instruction")) return nodetest_type_pi;

                break;

            case 't':
                if (name == PUGIXML_TEXT("text")) return nodetest_type_text;

                break;

            default:
                break;
        }

        return nodetest_none;
    }

    // PrimaryExpr ::= VariableReference | '(' Expr ')' | Literal | Number | FunctionCall
    xpath_ast_node* parse_primary_expression()
    {
        switch (_lexer.current()) {
            case lex_var_ref: {
                xpath_lexer_string name = _lexer.contents();

                if (!_variables) return error("Unknown variable: variable set is not provided");

                xpath_variable* var = 0;
                if (!get_variable_scratch(_scratch, _variables, name.begin, name.end, &var)) return error_oom();

                if (!var) return error("Unknown variable: variable set does not contain the given name");

                _lexer.next();

                return alloc_node(ast_variable, var->type(), var);
            }

            case lex_open_brace: {
                _lexer.next();

                xpath_ast_node* n = parse_expression();
                if (!n) return 0;

                if (_lexer.current() != lex_close_brace) return error("Expected ')' to match an opening '('");

                _lexer.next();

                return n;
            }

            case lex_quoted_string: {
                const char_t* value = alloc_string(_lexer.contents());
                if (!value) return 0;

                _lexer.next();

                return alloc_node(ast_string_constant, xpath_type_string, value);
            }

            case lex_number: {
                double value = 0;

                if (!convert_string_to_number_scratch(_scratch, _lexer.contents().begin, _lexer.contents().end, &value)) return error_oom();

                _lexer.next();

                return alloc_node(ast_number_constant, xpath_type_number, value);
            }

            case lex_string: {
                xpath_ast_node* args[2] = { 0 };
                size_t          argc    = 0;

                xpath_lexer_string function = _lexer.contents();
                _lexer.next();

                xpath_ast_node* last_arg = 0;

                if (_lexer.current() != lex_open_brace) return error("Unrecognized function call");
                _lexer.next();

                while (_lexer.current() != lex_close_brace) {
                    if (argc > 0) {
                        if (_lexer.current() != lex_comma) return error("No comma between function arguments");
                        _lexer.next();
                    }

                    xpath_ast_node* n = parse_expression();
                    if (!n) return 0;

                    if (argc < 2)
                        args[argc] = n;
                    else
                        last_arg->set_next(n);

                    argc++;
                    last_arg = n;
                }

                _lexer.next();

                return parse_function(function, argc, args);
            }

            default:
                return error("Unrecognizable primary expression");
        }
    }

    // FilterExpr ::= PrimaryExpr | FilterExpr Predicate
    // Predicate ::= '[' PredicateExpr ']'
    // PredicateExpr ::= Expr
    xpath_ast_node* parse_filter_expression()
    {
        xpath_ast_node* n = parse_primary_expression();
        if (!n) return 0;

        while (_lexer.current() == lex_open_square_brace) {
            _lexer.next();

            if (n->rettype() != xpath_type_node_set) return error("Predicate has to be applied to node set");

            xpath_ast_node* expr = parse_expression();
            if (!expr) return 0;

            n = alloc_node(ast_filter, n, expr, predicate_default);
            if (!n) return 0;

            if (_lexer.current() != lex_close_square_brace) return error("Expected ']' to match an opening '['");

            _lexer.next();
        }

        return n;
    }

    // Step ::= AxisSpecifier NodeTest Predicate* | AbbreviatedStep
    // AxisSpecifier ::= AxisName '::' | '@'?
    // NodeTest ::= NameTest | NodeType '(' ')' | 'processing-instruction' '(' Literal ')'
    // NameTest ::= '*' | NCName ':' '*' | QName
    // AbbreviatedStep ::= '.' | '..'
    xpath_ast_node* parse_step(xpath_ast_node* set)
    {
        if (set && set->rettype() != xpath_type_node_set) return error("Step has to be applied to node set");

        bool   axis_specified = false;
        axis_t axis           = axis_child;    // implied child axis

        if (_lexer.current() == lex_axis_attribute) {
            axis           = axis_attribute;
            axis_specified = true;

            _lexer.next();
        }
        else if (_lexer.current() == lex_dot) {
            _lexer.next();

            if (_lexer.current() == lex_open_square_brace) return error("Predicates are not allowed after an abbreviated step");

            return alloc_node(ast_step, set, axis_self, nodetest_type_node, 0);
        }
        else if (_lexer.current() == lex_double_dot) {
            _lexer.next();

            if (_lexer.current() == lex_open_square_brace) return error("Predicates are not allowed after an abbreviated step");

            return alloc_node(ast_step, set, axis_parent, nodetest_type_node, 0);
        }

        nodetest_t         nt_type = nodetest_none;
        xpath_lexer_string nt_name;

        if (_lexer.current() == lex_string) {
            // node name test
            nt_name = _lexer.contents();
            _lexer.next();

            // was it an axis name?
            if (_lexer.current() == lex_double_colon) {
                // parse axis name
                if (axis_specified) return error("Two axis specifiers in one step");

                axis = parse_axis_name(nt_name, axis_specified);

                if (!axis_specified) return error("Unknown axis");

                // read actual node test
                _lexer.next();

                if (_lexer.current() == lex_multiply) {
                    nt_type = nodetest_all;
                    nt_name = xpath_lexer_string();
                    _lexer.next();
                }
                else if (_lexer.current() == lex_string) {
                    nt_name = _lexer.contents();
                    _lexer.next();
                }
                else {
                    return error("Unrecognized node test");
                }
            }

            if (nt_type == nodetest_none) {
                // node type test or processing-instruction
                if (_lexer.current() == lex_open_brace) {
                    _lexer.next();

                    if (_lexer.current() == lex_close_brace) {
                        _lexer.next();

                        nt_type = parse_node_test_type(nt_name);

                        if (nt_type == nodetest_none) return error("Unrecognized node type");

                        nt_name = xpath_lexer_string();
                    }
                    else if (nt_name == PUGIXML_TEXT("processing-instruction")) {
                        if (_lexer.current() != lex_quoted_string)
                            return error("Only literals are allowed as arguments to processing-instruction()");

                        nt_type = nodetest_pi;
                        nt_name = _lexer.contents();
                        _lexer.next();

                        if (_lexer.current() != lex_close_brace) return error("Unmatched brace near processing-instruction()");
                        _lexer.next();
                    }
                    else {
                        return error("Unmatched brace near node type test");
                    }
                }
                // QName or NCName:*
                else {
                    if (nt_name.end - nt_name.begin > 2 && nt_name.end[-2] == ':' && nt_name.end[-1] == '*')    // NCName:*
                    {
                        nt_name.end--;    // erase *

                        nt_type = nodetest_all_in_namespace;
                    }
                    else {
                        nt_type = nodetest_name;
                    }
                }
            }
        }
        else if (_lexer.current() == lex_multiply) {
            nt_type = nodetest_all;
            _lexer.next();
        }
        else {
            return error("Unrecognized node test");
        }

        const char_t* nt_name_copy = alloc_string(nt_name);
        if (!nt_name_copy) return 0;

        xpath_ast_node* n = alloc_node(ast_step, set, axis, nt_type, nt_name_copy);
        if (!n) return 0;

        xpath_ast_node* last = 0;

        while (_lexer.current() == lex_open_square_brace) {
            _lexer.next();

            xpath_ast_node* expr = parse_expression();
            if (!expr) return 0;

            xpath_ast_node* pred = alloc_node(ast_predicate, 0, expr, predicate_default);
            if (!pred) return 0;

            if (_lexer.current() != lex_close_square_brace) return error("Expected ']' to match an opening '['");
            _lexer.next();

            if (last)
                last->set_next(pred);
            else
                n->set_right(pred);

            last = pred;
        }

        return n;
    }

    // RelativeLocationPath ::= Step | RelativeLocationPath '/' Step | RelativeLocationPath '//' Step
    xpath_ast_node* parse_relative_location_path(xpath_ast_node* set)
    {
        xpath_ast_node* n = parse_step(set);
        if (!n) return 0;

        while (_lexer.current() == lex_slash || _lexer.current() == lex_double_slash) {
            lexeme_t l = _lexer.current();
            _lexer.next();

            if (l == lex_double_slash) {
                n = alloc_node(ast_step, n, axis_descendant_or_self, nodetest_type_node, 0);
                if (!n) return 0;
            }

            n = parse_step(n);
            if (!n) return 0;
        }

        return n;
    }

    // LocationPath ::= RelativeLocationPath | AbsoluteLocationPath
    // AbsoluteLocationPath ::= '/' RelativeLocationPath? | '//' RelativeLocationPath
    xpath_ast_node* parse_location_path()
    {
        if (_lexer.current() == lex_slash) {
            _lexer.next();

            xpath_ast_node* n = alloc_node(ast_step_root, xpath_type_node_set);
            if (!n) return 0;

            // relative location path can start from axis_attribute, dot, double_dot, multiply and string lexemes; any other lexeme means
            // standalone root path
            lexeme_t l = _lexer.current();

            if (l == lex_string || l == lex_axis_attribute || l == lex_dot || l == lex_double_dot || l == lex_multiply)
                return parse_relative_location_path(n);
            else
                return n;
        }
        else if (_lexer.current() == lex_double_slash) {
            _lexer.next();

            xpath_ast_node* n = alloc_node(ast_step_root, xpath_type_node_set);
            if (!n) return 0;

            n = alloc_node(ast_step, n, axis_descendant_or_self, nodetest_type_node, 0);
            if (!n) return 0;

            return parse_relative_location_path(n);
        }

        // else clause moved outside of if because of bogus warning 'control may reach end of non-void function being inlined' in gcc 4.0.1
        return parse_relative_location_path(0);
    }

    // PathExpr ::= LocationPath
    //				| FilterExpr
    //				| FilterExpr '/' RelativeLocationPath
    //				| FilterExpr '//' RelativeLocationPath
    // UnionExpr ::= PathExpr | UnionExpr '|' PathExpr
    // UnaryExpr ::= UnionExpr | '-' UnaryExpr
    xpath_ast_node* parse_path_or_unary_expression()
    {
        // Clarification.
        // PathExpr begins with either LocationPath or FilterExpr.
        // FilterExpr begins with PrimaryExpr
        // PrimaryExpr begins with '$' in case of it being a variable reference,
        // '(' in case of it being an expression, string literal, number constant or
        // function call.
        if (_lexer.current() == lex_var_ref || _lexer.current() == lex_open_brace || _lexer.current() == lex_quoted_string ||
            _lexer.current() == lex_number || _lexer.current() == lex_string)
        {
            if (_lexer.current() == lex_string) {
                // This is either a function call, or not - if not, we shall proceed with location path
                const char_t* state = _lexer.state();

                while (PUGI__IS_CHARTYPE(*state, ct_space)) ++state;

                if (*state != '(') return parse_location_path();

                // This looks like a function call; however this still can be a node-test. Check it.
                if (parse_node_test_type(_lexer.contents()) != nodetest_none) return parse_location_path();
            }

            xpath_ast_node* n = parse_filter_expression();
            if (!n) return 0;

            if (_lexer.current() == lex_slash || _lexer.current() == lex_double_slash) {
                lexeme_t l = _lexer.current();
                _lexer.next();

                if (l == lex_double_slash) {
                    if (n->rettype() != xpath_type_node_set) return error("Step has to be applied to node set");

                    n = alloc_node(ast_step, n, axis_descendant_or_self, nodetest_type_node, 0);
                    if (!n) return 0;
                }

                // select from location path
                return parse_relative_location_path(n);
            }

            return n;
        }
        else if (_lexer.current() == lex_minus) {
            _lexer.next();

            // precedence 7+ - only parses union expressions
            xpath_ast_node* n = parse_expression(7);
            if (!n) return 0;

            return alloc_node(ast_op_negate, xpath_type_number, n);
        }
        else {
            return parse_location_path();
        }
    }

    struct binary_op_t
    {
        ast_type_t       asttype;
        xpath_value_type rettype;
        int              precedence;

        binary_op_t() : asttype(ast_unknown), rettype(xpath_type_none), precedence(0) {}

        binary_op_t(ast_type_t asttype_, xpath_value_type rettype_, int precedence_)
            : asttype(asttype_),
              rettype(rettype_),
              precedence(precedence_)
        {}

        static binary_op_t parse(xpath_lexer& lexer)
        {
            switch (lexer.current()) {
                case lex_string:
                    if (lexer.contents() == PUGIXML_TEXT("or"))
                        return binary_op_t(ast_op_or, xpath_type_boolean, 1);
                    else if (lexer.contents() == PUGIXML_TEXT("and"))
                        return binary_op_t(ast_op_and, xpath_type_boolean, 2);
                    else if (lexer.contents() == PUGIXML_TEXT("div"))
                        return binary_op_t(ast_op_divide, xpath_type_number, 6);
                    else if (lexer.contents() == PUGIXML_TEXT("mod"))
                        return binary_op_t(ast_op_mod, xpath_type_number, 6);
                    else
                        return binary_op_t();

                case lex_equal:
                    return binary_op_t(ast_op_equal, xpath_type_boolean, 3);

                case lex_not_equal:
                    return binary_op_t(ast_op_not_equal, xpath_type_boolean, 3);

                case lex_less:
                    return binary_op_t(ast_op_less, xpath_type_boolean, 4);

                case lex_greater:
                    return binary_op_t(ast_op_greater, xpath_type_boolean, 4);

                case lex_less_or_equal:
                    return binary_op_t(ast_op_less_or_equal, xpath_type_boolean, 4);

                case lex_greater_or_equal:
                    return binary_op_t(ast_op_greater_or_equal, xpath_type_boolean, 4);

                case lex_plus:
                    return binary_op_t(ast_op_add, xpath_type_number, 5);

                case lex_minus:
                    return binary_op_t(ast_op_subtract, xpath_type_number, 5);

                case lex_multiply:
                    return binary_op_t(ast_op_multiply, xpath_type_number, 6);

                case lex_union:
                    return binary_op_t(ast_op_union, xpath_type_node_set, 7);

                default:
                    return binary_op_t();
            }
        }
    };

    xpath_ast_node* parse_expression_rec(xpath_ast_node* lhs, int limit)
    {
        binary_op_t op = binary_op_t::parse(_lexer);

        while (op.asttype != ast_unknown && op.precedence >= limit) {
            _lexer.next();

            xpath_ast_node* rhs = parse_path_or_unary_expression();
            if (!rhs) return 0;

            binary_op_t nextop = binary_op_t::parse(_lexer);

            while (nextop.asttype != ast_unknown && nextop.precedence > op.precedence) {
                rhs = parse_expression_rec(rhs, nextop.precedence);
                if (!rhs) return 0;

                nextop = binary_op_t::parse(_lexer);
            }

            if (op.asttype == ast_op_union && (lhs->rettype() != xpath_type_node_set || rhs->rettype() != xpath_type_node_set))
                return error("Union operator has to be applied to node sets");

            lhs = alloc_node(op.asttype, op.rettype, lhs, rhs);
            if (!lhs) return 0;

            op = binary_op_t::parse(_lexer);
        }

        return lhs;
    }

    // Expr ::= OrExpr
    // OrExpr ::= AndExpr | OrExpr 'or' AndExpr
    // AndExpr ::= EqualityExpr | AndExpr 'and' EqualityExpr
    // EqualityExpr ::= RelationalExpr
    //					| EqualityExpr '=' RelationalExpr
    //					| EqualityExpr '!=' RelationalExpr
    // RelationalExpr ::= AdditiveExpr
    //					  | RelationalExpr '<' AdditiveExpr
    //					  | RelationalExpr '>' AdditiveExpr
    //					  | RelationalExpr '<=' AdditiveExpr
    //					  | RelationalExpr '>=' AdditiveExpr
    // AdditiveExpr ::= MultiplicativeExpr
    //					| AdditiveExpr '+' MultiplicativeExpr
    //					| AdditiveExpr '-' MultiplicativeExpr
    // MultiplicativeExpr ::= UnaryExpr
    //						  | MultiplicativeExpr '*' UnaryExpr
    //						  | MultiplicativeExpr 'div' UnaryExpr
    //						  | MultiplicativeExpr 'mod' UnaryExpr
    xpath_ast_node* parse_expression(int limit = 0)
    {
        xpath_ast_node* n = parse_path_or_unary_expression();
        if (!n) return 0;

        return parse_expression_rec(n, limit);
    }

    xpath_parser(const char_t* query, xpath_variable_set* variables, xpath_allocator* alloc, xpath_parse_result* result)
        : _alloc(alloc),
          _lexer(query),
          _query(query),
          _variables(variables),
          _result(result)
    {}

    xpath_ast_node* parse()
    {
        xpath_ast_node* n = parse_expression();
        if (!n) return 0;

        // check if there are unparsed tokens left
        if (_lexer.current() != lex_eof) return error("Incorrect query");

        return n;
    }

    static xpath_ast_node* parse(const char_t* query, xpath_variable_set* variables, xpath_allocator* alloc, xpath_parse_result* result)
    {
        xpath_parser parser(query, variables, alloc, result);

        return parser.parse();
    }
};

struct xpath_query_impl
{
    static xpath_query_impl* create()
    {
        void* memory = xml_memory::allocate(sizeof(xpath_query_impl));
        if (!memory) return 0;

        return new (memory) xpath_query_impl();
    }

    static void destroy(xpath_query_impl* impl)
    {
        // free all allocated pages
        impl->alloc.release();

        // free allocator memory (with the first page)
        xml_memory::deallocate(impl);
    }

    xpath_query_impl() : root(0), alloc(&block, &oom), oom(false)
    {
        block.next     = 0;
        block.capacity = sizeof(block.data);
    }

    xpath_ast_node*    root;
    xpath_allocator    alloc;
    xpath_memory_block block;
    bool               oom;
};

PUGI__FN impl::xpath_ast_node* evaluate_node_set_prepare(xpath_query_impl* impl)
{
    if (!impl) return 0;

    if (impl->root->rettype() != xpath_type_node_set) {
#        ifdef PUGIXML_NO_EXCEPTIONS
        return 0;
#        else
        xpath_parse_result res;
        res.error = "Expression does not evaluate to node set";

        throw xpath_exception(res);
#        endif
    }

    return impl->root;
}
PUGI__NS_END

namespace pugi
{
#        ifndef PUGIXML_NO_EXCEPTIONS
    PUGI__FN xpath_exception::xpath_exception(const xpath_parse_result& result_) : _result(result_)
    {
        assert(_result.error);
    }

    PUGI__FN const char* xpath_exception::what() const throw()
    {
        return _result.error;
    }

    PUGI__FN const xpath_parse_result& xpath_exception::result() const
    {
        return _result;
    }
#        endif

    PUGI__FN xpath_node::xpath_node() {}

    PUGI__FN xpath_node::xpath_node(const xml_node& node_) : _node(node_) {}

    PUGI__FN xpath_node::xpath_node(const xml_attribute& attribute_, const xml_node& parent_)
        : _node(attribute_ ? parent_ : xml_node()),
          _attribute(attribute_)
    {}

    PUGI__FN xml_node xpath_node::node() const
    {
        return _attribute ? xml_node() : _node;
    }

    PUGI__FN xml_attribute xpath_node::attribute() const
    {
        return _attribute;
    }

    PUGI__FN xml_node xpath_node::parent() const
    {
        return _attribute ? _node : _node.parent();
    }

    PUGI__FN static void unspecified_bool_xpath_node(xpath_node***) {}

    PUGI__FN xpath_node::operator xpath_node::unspecified_bool_type() const
    {
        return (_node || _attribute) ? unspecified_bool_xpath_node : 0;
    }

    PUGI__FN bool xpath_node::operator!() const
    {
        return !(_node || _attribute);
    }

    PUGI__FN bool xpath_node::operator==(const xpath_node& n) const
    {
        return _node == n._node && _attribute == n._attribute;
    }

    PUGI__FN bool xpath_node::operator!=(const xpath_node& n) const
    {
        return _node != n._node || _attribute != n._attribute;
    }

#        ifdef __BORLANDC__
    PUGI__FN bool operator&&(const xpath_node& lhs, bool rhs)
    {
        return (bool)lhs && rhs;
    }

    PUGI__FN bool operator||(const xpath_node& lhs, bool rhs)
    {
        return (bool)lhs || rhs;
    }
#        endif

    PUGI__FN void xpath_node_set::_assign(const_iterator begin_, const_iterator end_, type_t type_)
    {
        assert(begin_ <= end_);

        size_t size_ = static_cast<size_t>(end_ - begin_);

        // use internal buffer for 0 or 1 elements, heap buffer otherwise
        xpath_node* storage = (size_ <= 1) ? _storage : static_cast<xpath_node*>(impl::xml_memory::allocate(size_ * sizeof(xpath_node)));

        if (!storage) {
#        ifdef PUGIXML_NO_EXCEPTIONS
            return;
#        else
            throw std::bad_alloc();
#        endif
        }

        // deallocate old buffer
        if (_begin != _storage) impl::xml_memory::deallocate(_begin);

        // size check is necessary because for begin_ = end_ = nullptr, memcpy is UB
        if (size_) memcpy(storage, begin_, size_ * sizeof(xpath_node));

        _begin = storage;
        _end   = storage + size_;
        _type  = type_;
    }

#        ifdef PUGIXML_HAS_MOVE
    PUGI__FN void xpath_node_set::_move(xpath_node_set& rhs) PUGIXML_NOEXCEPT
    {
        _type       = rhs._type;
        _storage[0] = rhs._storage[0];
        _begin      = (rhs._begin == rhs._storage) ? _storage : rhs._begin;
        _end        = _begin + (rhs._end - rhs._begin);

        rhs._type  = type_unsorted;
        rhs._begin = rhs._storage;
        rhs._end   = rhs._storage;
    }
#        endif

    PUGI__FN xpath_node_set::xpath_node_set() : _type(type_unsorted), _begin(_storage), _end(_storage) {}

    PUGI__FN xpath_node_set::xpath_node_set(const_iterator begin_, const_iterator end_, type_t type_)
        : _type(type_unsorted),
          _begin(_storage),
          _end(_storage)
    {
        _assign(begin_, end_, type_);
    }

    PUGI__FN xpath_node_set::~xpath_node_set()
    {
        if (_begin != _storage) impl::xml_memory::deallocate(_begin);
    }

    PUGI__FN xpath_node_set::xpath_node_set(const xpath_node_set& ns) : _type(type_unsorted), _begin(_storage), _end(_storage)
    {
        _assign(ns._begin, ns._end, ns._type);
    }

    PUGI__FN xpath_node_set& xpath_node_set::operator=(const xpath_node_set& ns)
    {
        if (this == &ns) return *this;

        _assign(ns._begin, ns._end, ns._type);

        return *this;
    }

#        ifdef PUGIXML_HAS_MOVE
    PUGI__FN xpath_node_set::xpath_node_set(xpath_node_set&& rhs) PUGIXML_NOEXCEPT : _type(type_unsorted), _begin(_storage), _end(_storage)
    {
        _move(rhs);
    }

    PUGI__FN xpath_node_set& xpath_node_set::operator=(xpath_node_set&& rhs) PUGIXML_NOEXCEPT
    {
        if (this == &rhs) return *this;

        if (_begin != _storage) impl::xml_memory::deallocate(_begin);

        _move(rhs);

        return *this;
    }
#        endif

    PUGI__FN xpath_node_set::type_t xpath_node_set::type() const
    {
        return _type;
    }

    PUGI__FN size_t xpath_node_set::size() const
    {
        return _end - _begin;
    }

    PUGI__FN bool xpath_node_set::empty() const
    {
        return _begin == _end;
    }

    PUGI__FN const xpath_node& xpath_node_set::operator[](size_t index) const
    {
        assert(index < size());
        return _begin[index];
    }

    PUGI__FN xpath_node_set::const_iterator xpath_node_set::begin() const
    {
        return _begin;
    }

    PUGI__FN xpath_node_set::const_iterator xpath_node_set::end() const
    {
        return _end;
    }

    PUGI__FN void xpath_node_set::sort(bool reverse)
    {
        _type = impl::xpath_sort(_begin, _end, _type, reverse);
    }

    PUGI__FN xpath_node xpath_node_set::first() const
    {
        return impl::xpath_first(_begin, _end, _type);
    }

    PUGI__FN xpath_parse_result::xpath_parse_result() : error("Internal error"), offset(0) {}

    PUGI__FN xpath_parse_result::operator bool() const
    {
        return error == 0;
    }

    PUGI__FN const char* xpath_parse_result::description() const
    {
        return error ? error : "No error";
    }

    PUGI__FN xpath_variable::xpath_variable(xpath_value_type type_) : _type(type_), _next(0) {}

    PUGI__FN const char_t* xpath_variable::name() const
    {
        switch (_type) {
            case xpath_type_node_set:
                return static_cast<const impl::xpath_variable_node_set*>(this)->name;

            case xpath_type_number:
                return static_cast<const impl::xpath_variable_number*>(this)->name;

            case xpath_type_string:
                return static_cast<const impl::xpath_variable_string*>(this)->name;

            case xpath_type_boolean:
                return static_cast<const impl::xpath_variable_boolean*>(this)->name;

            default:
                assert(false && "Invalid variable type");    // unreachable
                return 0;
        }
    }

    PUGI__FN xpath_value_type xpath_variable::type() const
    {
        return _type;
    }

    PUGI__FN bool xpath_variable::get_boolean() const
    {
        return (_type == xpath_type_boolean) ? static_cast<const impl::xpath_variable_boolean*>(this)->value : false;
    }

    PUGI__FN double xpath_variable::get_number() const
    {
        return (_type == xpath_type_number) ? static_cast<const impl::xpath_variable_number*>(this)->value : impl::gen_nan();
    }

    PUGI__FN const char_t* xpath_variable::get_string() const
    {
        const char_t* value = (_type == xpath_type_string) ? static_cast<const impl::xpath_variable_string*>(this)->value : 0;
        return value ? value : PUGIXML_TEXT("");
    }

    PUGI__FN const xpath_node_set& xpath_variable::get_node_set() const
    {
        return (_type == xpath_type_node_set) ? static_cast<const impl::xpath_variable_node_set*>(this)->value : impl::dummy_node_set;
    }

    PUGI__FN bool xpath_variable::set(bool value)
    {
        if (_type != xpath_type_boolean) return false;

        static_cast<impl::xpath_variable_boolean*>(this)->value = value;
        return true;
    }

    PUGI__FN bool xpath_variable::set(double value)
    {
        if (_type != xpath_type_number) return false;

        static_cast<impl::xpath_variable_number*>(this)->value = value;
        return true;
    }

    PUGI__FN bool xpath_variable::set(const char_t* value)
    {
        if (_type != xpath_type_string) return false;

        impl::xpath_variable_string* var = static_cast<impl::xpath_variable_string*>(this);

        // duplicate string
        size_t size = (impl::strlength(value) + 1) * sizeof(char_t);

        char_t* copy = static_cast<char_t*>(impl::xml_memory::allocate(size));
        if (!copy) return false;

        memcpy(copy, value, size);

        // replace old string
        if (var->value) impl::xml_memory::deallocate(var->value);
        var->value = copy;

        return true;
    }

    PUGI__FN bool xpath_variable::set(const xpath_node_set& value)
    {
        if (_type != xpath_type_node_set) return false;

        static_cast<impl::xpath_variable_node_set*>(this)->value = value;
        return true;
    }

    PUGI__FN xpath_variable_set::xpath_variable_set()
    {
        for (size_t i = 0; i < sizeof(_data) / sizeof(_data[0]); ++i) _data[i] = 0;
    }

    PUGI__FN xpath_variable_set::~xpath_variable_set()
    {
        for (size_t i = 0; i < sizeof(_data) / sizeof(_data[0]); ++i) _destroy(_data[i]);
    }

    PUGI__FN xpath_variable_set::xpath_variable_set(const xpath_variable_set& rhs)
    {
        for (size_t i = 0; i < sizeof(_data) / sizeof(_data[0]); ++i) _data[i] = 0;

        _assign(rhs);
    }

    PUGI__FN xpath_variable_set& xpath_variable_set::operator=(const xpath_variable_set& rhs)
    {
        if (this == &rhs) return *this;

        _assign(rhs);

        return *this;
    }

#        ifdef PUGIXML_HAS_MOVE
    PUGI__FN xpath_variable_set::xpath_variable_set(xpath_variable_set&& rhs) PUGIXML_NOEXCEPT
    {
        for (size_t i = 0; i < sizeof(_data) / sizeof(_data[0]); ++i) {
            _data[i]     = rhs._data[i];
            rhs._data[i] = 0;
        }
    }

    PUGI__FN xpath_variable_set& xpath_variable_set::operator=(xpath_variable_set&& rhs) PUGIXML_NOEXCEPT
    {
        for (size_t i = 0; i < sizeof(_data) / sizeof(_data[0]); ++i) {
            _destroy(_data[i]);

            _data[i]     = rhs._data[i];
            rhs._data[i] = 0;
        }

        return *this;
    }
#        endif

    PUGI__FN void xpath_variable_set::_assign(const xpath_variable_set& rhs)
    {
        xpath_variable_set temp;

        for (size_t i = 0; i < sizeof(_data) / sizeof(_data[0]); ++i)
            if (rhs._data[i] && !_clone(rhs._data[i], &temp._data[i])) return;

        _swap(temp);
    }

    PUGI__FN void xpath_variable_set::_swap(xpath_variable_set& rhs)
    {
        for (size_t i = 0; i < sizeof(_data) / sizeof(_data[0]); ++i) {
            xpath_variable* chain = _data[i];

            _data[i]     = rhs._data[i];
            rhs._data[i] = chain;
        }
    }

    PUGI__FN xpath_variable* xpath_variable_set::_find(const char_t* name) const
    {
        const size_t hash_size = sizeof(_data) / sizeof(_data[0]);
        size_t       hash      = impl::hash_string(name) % hash_size;

        // look for existing variable
        for (xpath_variable* var = _data[hash]; var; var = var->_next)
            if (impl::strequal(var->name(), name)) return var;

        return 0;
    }

    PUGI__FN bool xpath_variable_set::_clone(xpath_variable* var, xpath_variable** out_result)
    {
        xpath_variable* last = 0;

        while (var) {
            // allocate storage for new variable
            xpath_variable* nvar = impl::new_xpath_variable(var->_type, var->name());
            if (!nvar) return false;

            // link the variable to the result immediately to handle failures gracefully
            if (last)
                last->_next = nvar;
            else
                *out_result = nvar;

            last = nvar;

            // copy the value; this can fail due to out-of-memory conditions
            if (!impl::copy_xpath_variable(nvar, var)) return false;

            var = var->_next;
        }

        return true;
    }

    PUGI__FN void xpath_variable_set::_destroy(xpath_variable* var)
    {
        while (var) {
            xpath_variable* next = var->_next;

            impl::delete_xpath_variable(var->_type, var);

            var = next;
        }
    }

    PUGI__FN xpath_variable* xpath_variable_set::add(const char_t* name, xpath_value_type type)
    {
        const size_t hash_size = sizeof(_data) / sizeof(_data[0]);
        size_t       hash      = impl::hash_string(name) % hash_size;

        // look for existing variable
        for (xpath_variable* var = _data[hash]; var; var = var->_next)
            if (impl::strequal(var->name(), name)) return var->type() == type ? var : 0;

        // add new variable
        xpath_variable* result = impl::new_xpath_variable(type, name);

        if (result) {
            result->_next = _data[hash];

            _data[hash] = result;
        }

        return result;
    }

    PUGI__FN bool xpath_variable_set::set(const char_t* name, bool value)
    {
        xpath_variable* var = add(name, xpath_type_boolean);
        return var ? var->set(value) : false;
    }

    PUGI__FN bool xpath_variable_set::set(const char_t* name, double value)
    {
        xpath_variable* var = add(name, xpath_type_number);
        return var ? var->set(value) : false;
    }

    PUGI__FN bool xpath_variable_set::set(const char_t* name, const char_t* value)
    {
        xpath_variable* var = add(name, xpath_type_string);
        return var ? var->set(value) : false;
    }

    PUGI__FN bool xpath_variable_set::set(const char_t* name, const xpath_node_set& value)
    {
        xpath_variable* var = add(name, xpath_type_node_set);
        return var ? var->set(value) : false;
    }

    PUGI__FN xpath_variable* xpath_variable_set::get(const char_t* name)
    {
        return _find(name);
    }

    PUGI__FN const xpath_variable* xpath_variable_set::get(const char_t* name) const
    {
        return _find(name);
    }

    PUGI__FN xpath_query::xpath_query(const char_t* query, xpath_variable_set* variables) : _impl(0)
    {
        impl::xpath_query_impl* qimpl = impl::xpath_query_impl::create();

        if (!qimpl) {
#        ifdef PUGIXML_NO_EXCEPTIONS
            _result.error = "Out of memory";
#        else
            throw std::bad_alloc();
#        endif
        }
        else {
            using impl::auto_deleter;    // MSVC7 workaround
            auto_deleter<impl::xpath_query_impl> impl(qimpl, impl::xpath_query_impl::destroy);

            qimpl->root = impl::xpath_parser::parse(query, variables, &qimpl->alloc, &_result);

            if (qimpl->root) {
                qimpl->root->optimize(&qimpl->alloc);

                _impl         = impl.release();
                _result.error = 0;
            }
            else {
#        ifdef PUGIXML_NO_EXCEPTIONS
                if (qimpl->oom) _result.error = "Out of memory";
#        else
                if (qimpl->oom) throw std::bad_alloc();
                throw xpath_exception(_result);
#        endif
            }
        }
    }

    PUGI__FN xpath_query::xpath_query() : _impl(0) {}

    PUGI__FN xpath_query::~xpath_query()
    {
        if (_impl) impl::xpath_query_impl::destroy(static_cast<impl::xpath_query_impl*>(_impl));
    }

#        ifdef PUGIXML_HAS_MOVE
    PUGI__FN xpath_query::xpath_query(xpath_query&& rhs) PUGIXML_NOEXCEPT
    {
        _impl       = rhs._impl;
        _result     = rhs._result;
        rhs._impl   = 0;
        rhs._result = xpath_parse_result();
    }

    PUGI__FN xpath_query& xpath_query::operator=(xpath_query&& rhs) PUGIXML_NOEXCEPT
    {
        if (this == &rhs) return *this;

        if (_impl) impl::xpath_query_impl::destroy(static_cast<impl::xpath_query_impl*>(_impl));

        _impl       = rhs._impl;
        _result     = rhs._result;
        rhs._impl   = 0;
        rhs._result = xpath_parse_result();

        return *this;
    }
#        endif

    PUGI__FN xpath_value_type xpath_query::return_type() const
    {
        if (!_impl) return xpath_type_none;

        return static_cast<impl::xpath_query_impl*>(_impl)->root->rettype();
    }

    PUGI__FN bool xpath_query::evaluate_boolean(const xpath_node& n) const
    {
        if (!_impl) return false;

        impl::xpath_context    c(n, 1, 1);
        impl::xpath_stack_data sd;

        bool r = static_cast<impl::xpath_query_impl*>(_impl)->root->eval_boolean(c, sd.stack);

        if (sd.oom) {
#        ifdef PUGIXML_NO_EXCEPTIONS
            return false;
#        else
            throw std::bad_alloc();
#        endif
        }

        return r;
    }

    PUGI__FN double xpath_query::evaluate_number(const xpath_node& n) const
    {
        if (!_impl) return impl::gen_nan();

        impl::xpath_context    c(n, 1, 1);
        impl::xpath_stack_data sd;

        double r = static_cast<impl::xpath_query_impl*>(_impl)->root->eval_number(c, sd.stack);

        if (sd.oom) {
#        ifdef PUGIXML_NO_EXCEPTIONS
            return impl::gen_nan();
#        else
            throw std::bad_alloc();
#        endif
        }

        return r;
    }

#        ifndef PUGIXML_NO_STL
    PUGI__FN string_t xpath_query::evaluate_string(const xpath_node& n) const
    {
        if (!_impl) return string_t();

        impl::xpath_context    c(n, 1, 1);
        impl::xpath_stack_data sd;

        impl::xpath_string r = static_cast<impl::xpath_query_impl*>(_impl)->root->eval_string(c, sd.stack);

        if (sd.oom) {
#            ifdef PUGIXML_NO_EXCEPTIONS
            return string_t();
#            else
            throw std::bad_alloc();
#            endif
        }

        return string_t(r.c_str(), r.length());
    }
#        endif

    PUGI__FN size_t xpath_query::evaluate_string(char_t* buffer, size_t capacity, const xpath_node& n) const
    {
        impl::xpath_context    c(n, 1, 1);
        impl::xpath_stack_data sd;

        impl::xpath_string r = _impl ? static_cast<impl::xpath_query_impl*>(_impl)->root->eval_string(c, sd.stack) : impl::xpath_string();

        if (sd.oom) {
#        ifdef PUGIXML_NO_EXCEPTIONS
            r = impl::xpath_string();
#        else
            throw std::bad_alloc();
#        endif
        }

        size_t full_size = r.length() + 1;

        if (capacity > 0) {
            size_t size = (full_size < capacity) ? full_size : capacity;
            assert(size > 0);

            memcpy(buffer, r.c_str(), (size - 1) * sizeof(char_t));
            buffer[size - 1] = 0;
        }

        return full_size;
    }

    PUGI__FN xpath_node_set xpath_query::evaluate_node_set(const xpath_node& n) const
    {
        impl::xpath_ast_node* root = impl::evaluate_node_set_prepare(static_cast<impl::xpath_query_impl*>(_impl));
        if (!root) return xpath_node_set();

        impl::xpath_context    c(n, 1, 1);
        impl::xpath_stack_data sd;

        impl::xpath_node_set_raw r = root->eval_node_set(c, sd.stack, impl::nodeset_eval_all);

        if (sd.oom) {
#        ifdef PUGIXML_NO_EXCEPTIONS
            return xpath_node_set();
#        else
            throw std::bad_alloc();
#        endif
        }

        return xpath_node_set(r.begin(), r.end(), r.type());
    }

    PUGI__FN xpath_node xpath_query::evaluate_node(const xpath_node& n) const
    {
        impl::xpath_ast_node* root = impl::evaluate_node_set_prepare(static_cast<impl::xpath_query_impl*>(_impl));
        if (!root) return xpath_node();

        impl::xpath_context    c(n, 1, 1);
        impl::xpath_stack_data sd;

        impl::xpath_node_set_raw r = root->eval_node_set(c, sd.stack, impl::nodeset_eval_first);

        if (sd.oom) {
#        ifdef PUGIXML_NO_EXCEPTIONS
            return xpath_node();
#        else
            throw std::bad_alloc();
#        endif
        }

        return r.first();
    }

    PUGI__FN const xpath_parse_result& xpath_query::result() const
    {
        return _result;
    }

    PUGI__FN static void unspecified_bool_xpath_query(xpath_query***) {}

    PUGI__FN xpath_query::operator xpath_query::unspecified_bool_type() const
    {
        return _impl ? unspecified_bool_xpath_query : 0;
    }

    PUGI__FN bool xpath_query::operator!() const
    {
        return !_impl;
    }

    PUGI__FN xpath_node xml_node::select_node(const char_t* query, xpath_variable_set* variables) const
    {
        xpath_query q(query, variables);
        return q.evaluate_node(*this);
    }

    PUGI__FN xpath_node xml_node::select_node(const xpath_query& query) const
    {
        return query.evaluate_node(*this);
    }

    PUGI__FN xpath_node_set xml_node::select_nodes(const char_t* query, xpath_variable_set* variables) const
    {
        xpath_query q(query, variables);
        return q.evaluate_node_set(*this);
    }

    PUGI__FN xpath_node_set xml_node::select_nodes(const xpath_query& query) const
    {
        return query.evaluate_node_set(*this);
    }

    PUGI__FN xpath_node xml_node::select_single_node(const char_t* query, xpath_variable_set* variables) const
    {
        xpath_query q(query, variables);
        return q.evaluate_node(*this);
    }

    PUGI__FN xpath_node xml_node::select_single_node(const xpath_query& query) const
    {
        return query.evaluate_node(*this);
    }
}    // namespace pugi

#    endif

#    ifdef __BORLANDC__
#        pragma option pop
#    endif

// Intel C++ does not properly keep warning state for function templates,
// so popping warning state at the end of translation unit leads to warnings in the middle.
#    if defined(_MSC_VER) && !defined(__INTEL_COMPILER)
#        pragma warning(pop)
#    endif

#    if defined(_MSC_VER) && defined(__c2__)
#        pragma clang diagnostic pop
#    endif

// Undefine all local macros (makes sure we're not leaking macros in header-only mode)
#    undef PUGI__NO_INLINE
#    undef PUGI__UNLIKELY
#    undef PUGI__STATIC_ASSERT
#    undef PUGI__DMC_VOLATILE
#    undef PUGI__UNSIGNED_OVERFLOW
#    undef PUGI__MSVC_CRT_VERSION
#    undef PUGI__SNPRINTF
#    undef PUGI__NS_BEGIN
#    undef PUGI__NS_END
#    undef PUGI__FN
#    undef PUGI__FN_NO_INLINE
#    undef PUGI__GETHEADER_IMPL
#    undef PUGI__GETPAGE_IMPL
#    undef PUGI__GETPAGE
#    undef PUGI__NODETYPE
#    undef PUGI__IS_CHARTYPE_IMPL
#    undef PUGI__IS_CHARTYPE
#    undef PUGI__IS_CHARTYPEX
#    undef PUGI__ENDSWITH
#    undef PUGI__SKIPWS
#    undef PUGI__OPTSET
#    undef PUGI__PUSHNODE
#    undef PUGI__POPNODE
#    undef PUGI__SCANFOR
#    undef PUGI__SCANWHILE
#    undef PUGI__SCANWHILE_UNROLL
#    undef PUGI__ENDSEG
#    undef PUGI__THROW_ERROR
#    undef PUGI__CHECK_ERROR

#endif

/**
 * Copyright (c) 2006-2019 Arseny Kapoulkine
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */
